Primality Certificate for (978^3061-1)/977

Andy Steward9,151 digits17 November 2001
Originally by A.A.D.Steward 2001

This certificate uses a theorem of Konyagin and Pomerance to prove an integer N prime by making use of a partial prime factorization of N-1.

Factorizing N-1

As N is a Generalized Repunit, we make use of the algebraic factorization of N-1 to arrive at the following 30.184173% factorization of N-1:

From Factorisation
9782 · 3 · 163
Φ211 · 89
Φ313 · 73651
Φ45 · 191297
Φ5131 · 431 · 2371 · 6841
Φ67 · 136501
Φ919 · 37 · 181 · 13033 · 527660803
Φ10913927156411
Φ12914860685773
Φ15211 · 3962635194093086216701
Φ17239 · 1780924897 · 3686663235727 · 446878019194305924716591
Φ18271 · 3907 · 826457311549
Φ205 · 101 · 1657368216676707235381
Φ3031 · 3447169111 · 7840258671811
Φ34647 · 139537 · 48031189 · 225493836781 · 715692001388179083341
Φ36397 · 30853 · 38197 · 1354944817 · 1207890286573357
Φ458821 · 62731 · 2876131 · 460566491721348841363081 · p33
Φ51613 · 3571 · 407083 · 2867215207 · 115426330607540976781 · p55
Φ6061 · 4621 · 681698116441 · 1241468322481 · 2936490435271021861
Φ68137 · 3201899856457399943773 · 3657805283396483997135705593 · p45
Φ853061 · 8501 · 14056451 · 16429991 · 2952175801 · 288183260089423751491 · 2055638874672658997680531 · c116
Φ902251 · 27514171 · 178832535009211 · p47
Φ102103 · 307 · 2551 · 4591 · 461402101 · p76
Φ153404533 · 1620271 · 1243206703 · 1597534507 · c257
Φ1706277955284441 · 173267891982943215442211 · 92589933809629954778419111 · c130
Φ1806121 · 18181 · 1153441 · 1146723841 · p121
Φ204409 · 10043329 · 31111309365044809 · c166
Φ25599242747117166530971 · c363
Φ3061531 · 209886704479 · c273
Φ3402853521162101489661 · c365
Φ510349374481 · 417419670931 · 98588814302193361 · p346
Φ6123673 · 1743068982997 · c559
Φ765667402626614041 · p1134
Φ10201021 · 1165861 · 18326448121 · c747
Φ153078031 · 582931 · 852211 · 7582681 · c1125
Φ306012241 · c2293

From this partial factorization, we use sufficient of the largest prime factors of N-1 so that their product F is at least N 3/10 :

2922 3506640393 7101962585 2037138302 1523386169 8328265522 5818177969 5546430584 2305656236 1594064830 7472169242 3554434036 6043941183 2536052125 6591225079 5438270321 5918992475 6840612752 7287344413 9136811661 2685072108 2036198379 8254320672 3440513933 8019365292 5035772667 4765231801 4591968937 0026648638 4777140260 2082161059 7102395470 1313152590 2157057655 9690529687 3450042134 1190823397 8036949898 9668606549 9876310031 0808278360 9529308405 1385089483 6317886731 0929680904 6610247205 0999238213 5533917980 2149308625 1949782093 8771045762 4192174989 8545395581 7626695450 3680989194 1666113741 1136600671 4747869529 8242982458 9745392561 2929134483 2089733537 1359677089 5528622199 6243867706 8071113519 6863209330 1057823540 7704466309 7267564833 8893314427 7698762944 5028636505 1008363963 5896893751 3660169872 3578543675 8114138213 0277736313 4308964334 9352799901 9180482811 8113504008 3250938644 0537493150 7035275765 3860526574 8230120362 1826792000 7405960873 5211560171 6791993841 7926999160 8413215301 5084937974 4521500875 9083013046 3578913427 2208631977 6510201664 5936896732 6816659343 4453050523 2618749872 1895716067 9019228276 6135247039 8560030822 2890614381 4037595269 2882584970 3763492671 0694045311 1801000561
402937 6426384709 8700309742 8402334723 1606922194 6906042722 8361350316 6396005597 0760261747 3715928236 1805714834 3426119525 6252037965 1611270792 4950149727 4972652069 5941847597 1112228728 2288300811 3220623485 8178127147 4485243442 7720301906 0664228777 8775944429 8286852868 0971195448 5519525599 5368314052 9733223069 9018408836 8477066401 4640309196 0085643791 5883603681
2 3354504470 2578748744 4217786282 8019256681 5695108012 3889115211 0322584472 3289544258 4652270928 5804990308 6723104001 4540281701
287484 3915610910 8044103865 6874826283 9491907863 0278120456 6446447701 8108796891
16622 6626223010 9786219327 2398381767 2087508976 2720860497
5293635 7599825170 7680046591 2487157011 5115745651
30583 9802414146 9415850783 3343378461 2532758449
799 8922345691 3181007223 7556153741
36578052 8339648399 7135705593
925899 3380962995 4778419111
20556 3887467265 8997680531
4605 6649172134 8841363081
4468 7801919430 5924716591
1732 6789198294 3215442211
39 6263519409 3086216701
32 0189985645 7399943773
16 5736821667 6707235381
7 1569200138 8179083341
2 8818326008 9423751491
1 1542633060 7540976781
9924274711 7166530971
293649043 5271021861
285352116 2101489661
9858881 4302193361
3111130 9365044809
120789 0286573357
66740 2626614041
17883 2535009211
784 0258671811
627 7955284441
368 6663235727
174 3068982997
124 1468322481
91 4860685773
91 3927156411
82 6457311549
68 1698116441
41 7419670931
22 5493836781
20 9886704479
1 8326448121
3447169111
2952175801
2867215207
1780924897
1597534507
1354944817
1243206703
1146723841
527660803
461402101
349374481
48031189
27514171
16429991
14056451
10043329
7582681
2876131
1620271
1165861
1153441
852211
582931
407083
404533
191297
139537
136501
78031
73651
62731
38197
30853
18181
13033
12241
8821
8501
6841
6121
4621
4591
3907
3673
3571
3061
2551
2371
2251
1531
1021
647
613
431
409
397
307
271
239
211
181
163
137
131
103
101
89
61
37
31
19
13
11
7
52
3
2

Note that all prime factors listed above have been proven. As primes of under 250 decimal digits can be verified in a few seconds, proof of their primality is not included here, in order to save space. Larger prime factors can take from hours to months to prove; certificates for all such factors have been PKZIPped into this file.

We set R = (N-1)/F. Note that GCD(F,R)=1 and Log(F)/Log(N) = 30.184173%

Finding a Witness to Primality

Next, we find an integer witness w such that for each prime factor p of N-1, w(N-1) ≡ 1 mod N and GCD(w(N-1)/p-1,N) = 1. In this case, w = 7 suffices.

Express N in base F

As F3 < N < F4 and N ≡ 1 (mod F), we can let N = c3·F3 + c2·F2 + c1·F + 1. Let c4 = c3·F+c2.

Square Checks

For t = 0 to 5, we prove that Q(t) = (c1+t·F)2+4·t-4·c4 is not a perfect square. This is done by checking whether Q(t) is a quadratic residue modulo a variety of bases. If it happens to be a QR in all of the bases, we calculate s = floor(sqrt(Q(t))) and show that s2 < Q(t).

Continued Fraction

We approximate c1/F by a continued fraction u/v such that v is maximal while remaining less than F2 / N1/2 = 561001778 1855811376 4034652723 3328104879 8534879542 4490091928 9555132921 8761697363 5381478279 7349709138 9729914909 4454036559 6154368101 5048203780 6174998372 2622245959 7174298638 0855250533 2414308428 2209940411 0786562873 0288227377 2723169192 9397583591 7595770549 6166028769 4187320898 2308690629 8602446450 9471521798 6190526893 1787851358 4759267888 1000425236 9633710161 6418872036 5494440289 3231964217 2375307700 2195859601 7544340411 4081242240 9287821439 8180300502 6373240262 8441392264 1766334152 6262902817 2569315308 0595349879 0540630075 4452260308 1930824809 3681207813 5587980583 0755732420 6018771138 5183204386 5363420648 7039823500 9961393299 2633389096 5004608012 7780439662 0142926535 9602107394 2676983579 7001085523 3638864578 7707699363 3919910432 8269116400 6315692006 7135627659 3268340520 2504313903 3015497060 7037856236 6851605454 7622373127 9010765127 5968228590 4290595493 1029995424 6186566587 7969216299 3173968863 0014294045 7553403156 0341486310 2544880416 1972533873 5406196932 4620155388 2068738768.

With those constraints, the unique continued fraction is: {0, 17, 2, 14, 1, 2, 1, 1, 2, 14, 2, 1, 1, 1, 2, 2, 2, 1, 4, 5, 3, 3, 3, 2, 3, 35, 1, 3, 1, 2, 1, 1, 1, 1, 1, 14, 1, 56, 3, 2, 1, 17, 9, 6, 7, 2, 176, 1, 22, 68, 4, 1, 4, 2, 1, 9, 5, 26, 1, 1, 2, 1, 2, 2, 1, 3, 1, 1, 2, 1, 6, 1, 1, 34, 1, 2, 3, 8, 2, 2, 1, 34, 1, 4, 5, 2, 2, 1, 16, 1, 2, 2, 15, 1, 2, 18, 3, 7, 2, 1, 1, 1, 4, 1, 6, 1, 11, 2, 1, 1, 7, 1, 1, 2, 14, 2, 2, 11, 2, 7, 1, 1, 97, 2, 1, 7, 4, 2, 4, 1, 1, 1, 1, 2, 8, 1, 2, 1, 4, 3, 1, 12, 1, 1, 1, 27, 4, 8, 1, 1, 3, 1, 2, 2, 1, 3, 1, 1, 2, 2, 2, 1, 6, 2, 1, 2, 1, 1, 105, 2, 10, 2, 1, 1, 6, 8, 29, 2, 7, 9, 1, 1, 1, 4, 1, 3, 1, 1, 1, 3, 1, 8, 3, 56, 1, 6, 1, 1, 1, 1, 59, 3, 5, 3, 2, 2, 1, 1, 5, 1, 3, 1, 1, 3, 1, 1, 1, 2, 12, 5, 1, 3, 1, 13, 1, 4, 1, 1, 1, 3, 1, 2, 1, 1, 1, 1, 106, 1, 1, 1, 1, 494, 1, 1, 11, 89, 1, 1, 1, 16, 4, 1, 66, 2, 1, 2, 4, 1, 11, 1, 17, 2, 2, 3, 1, 1, 2, 18, 13, 3, 1, 2, 8, 3, 9, 1, 3, 7, 6, 1, 1, 25, 2, 14, 2, 5, 4, 5, 1, 14, 1, 10, 2, 18, 2, 10, 8, 3, 1, 2, 4, 1, 8, 1, 7, 1, 12, 1, 8, 16, 1, 3, 3, 15, 1, 4, 1, 2, 1, 18, 2, 6, 2, 2, 1, 1, 4, 1, 1, 1, 1, 16, 3, 5, 1, 6, 2, 3, 6, 1, 1, 3, 2, 1, 1, 1, 8, 1, 8, 127, 10, 1, 85, 4, 2, 1, 1, 7, 1, 4, 15, 1, 1, 18, 3, 6, 1, 1, 2, 2, 1, 12, 1, 2, 9, 5, 5, 1, 8, 1, 9, 1, 2, 4, 1, 2, 11, 1, 1, 42, 1, 3, 1, 2, 1, 1, 2, 1, 1, 1, 1, 27, 1, 1, 1, 2, 1, 7, 1, 4, 1, 10, 1, 4, 1, 7, 1, 3, 7, 13, 14, 3, 1, 2, 1, 1, 1, 2, 251, 1, 1, 2, 10, 1, 4, 1, 1, 11, 1, 24, 1, 1, 1, 1, 1, 2, 5, 2, 2, 1, 1191, 1, 31, 1, 10, 2, 1, 3, 17, 1, 1, 2, 2, 1, 1, 5, 2, 8, 3, 2, 5, 1, 3, 113, 1, 2, 3, 1, 1, 14, 2, 10, 8, 2, 8, 2, 1, 1, 1, 4, 1, 1, 5, 20, 3, 3, 2, 3, 5, 12, 1, 11, 1, 8, 4, 27, 1, 1, 1, 3, 1, 1, 12, 10, 1, 6, 4, 2, 54, 1, 4, 2, 1, 1, 3, 1, 2, 15, 8, 1, 10, 2, 28, 6, 3, 2, 1, 2, 34, 1, 1, 12, 1, 5, 1, 1, 1, 5, 2, 4, 92, 3, 4, 1, 1, 1, 1, 2, 29, 2, 10, 1, 1, 1, 1, 3, 1, 5, 1, 13, 7, 65, 15, 1, 1, 10, 10, 2, 1, 4, 1, 1, 1, 1, 7, 4, 1, 1, 4, 8, 1, 49, 1, 29, 2, 9, 7, 48, 4, 1, 1, 36, 1, 3, 8, 1, 1, 1, 2, 1, 2, 2, 2, 1, 22, 1, 1, 1, 47, 4, 2, 1, 4, 1, 96, 4, 1, 93, 1, 18, 2, 5, 20, 1, 1, 7, 3, 1, 4, 2, 1, 16, 2, 1, 1, 1, 3, 2, 1, 1, 1, 1, 7, 3, 1, 6, 1, 2, 6, 10, 1, 1, 2, 2, 1, 1, 1, 1, 3, 8, 3, 3, 1, 5, 1, 2, 3, 3, 1, 1, 1, 1, 2, 9, 1, 6, 1, 5, 1404, 1, 2, 1, 1, 1, 41, 12, 1, 1, 1, 1, 16, 1, 5, 1, 143, 2, 3, 5, 5, 1, 19, 2, 8, 2, 1, 1, 1, 2, 2, 6, 1, 2, 3, 1, 3, 3, 1, 2, 1, 2, 2, 4, 1, 6, 9, 2, 1, 2, 3, 6, 1, 58, 8, 3, 1, 1, 6, 1, 1, 1, 1, 234, 3, 2, 1, 28, 1, 10, 1, 28, 1, 18, 1, 6, 1, 38, 3, 2, 7, 1, 1, 5, 1, 9, 3, 9, 1, 7, 1, 1, 76, 11, 15, 1, 1, 1, 1, 1, 4, 5, 6, 2, 1, 138, 1, 2, 1, 5, 2, 3, 1, 3, 9, 1, 1, 2, 18, 4, 14, 52, 50, 1, 2, 1, 10, 4, 2, 2, 12, 6, 4, 1, 1, 1, 1, 4, 2, 2, 2, 10, 8, 1, 16, 1, 2, 5, 1, 2, 1, 5, 2, 1, 1, 1, 16, 13, 2, 2, 4, 1, 2, 1, 2, 1, 3, 1, 2, 1, 15, 1, 1, 3, 1, 5, 7, 2, 13, 19, 2, 1, 12, 1, 5, 1, 159, 1, 1, 37, 1, 13, 1, 1, 825, 1, 1, 1, 9, 1, 1, 1, 1, 2, 6, 1, 1, 1, 1, 2, 21, 1, 4, 1, 27, 9, 1, 9, 2, 1, 2, 2, 6, 2, 1, 6, 6, 12, 1, 14, 1, 3, 2, 1, 2, 2, 1, 16, 1, 1, 1, 1, 1, 13, 1, 378, 1, 2, 9, 1, 2, 1, 1, 7, 31, 4, 2, 1, 8, 1, 3, 2, 1, 2, 1, 1, 11, 1, 1, 3, 1, 20, 57, 3, 46, 2, 1, 19, 3, 18, 1, 4, 7, 2, 1, 2, 1, 5, 1, 2, 3, 1, 2, 1, 1, 5, 1, 4, 1, 8, 4, 1, 1, 7, 2, 1, 169, 49, 7, 6, 22, 1, 12, 2, 2, 1, 3, 77, 1, 6, 1, 6, 7, 2, 3, 3, 1, 26, 1, 3, 5, 8, 1, 4, 1, 2, 1, 3, 1, 2, 10, 5, 1, 1, 2, 11, 1, 3, 36, 3, 6, 5, 1, 28, 4, 4, 1, 3, 1, 3, 1, 1, 1, 30, 3, 13, 1, 8, 4, 1, 2, 4, 2, 2, 1, 1, 2, 2, 17, 1, 1, 1, 5, 4, 6, 33, 2, 8, 1, 5, 2, 6, 1, 2, 1, 3, 49, 5, 3, 62, 1, 2, 1, 1, 1, 3, 23, 6, 2, 10, 1, 4, 5, 2, 2, 85, 2, 7, 2, 1, 5, 85, 1, 4, 7, 3, 1, 7, 1, 463, 1, 6, 1, 2, 23, 1, 1, 4, 1, 1, 3, 1, 1, 18, 2, 1, 1, 1, 1, 2, 1, 13, 1, 1, 3, 24, 3, 7, 64, 2, 5, 1, 7, 1, 1, 2, 2, 1, 1, 1, 1, 1, 1, 2, 3, 40, 1, 1, 12, 1, 1, 1, 3, 6, 5, 1, 2, 3, 3, 4, 1, 3, 4, 51, 2, 26, 1, 1, 2, 6, 1, 2, 4, 6, 1, 7, 4, 7, 2, 11, 5, 2, 2, 7, 1, 2, 2, 16, 1, 4, 1, 1, 2, 1, 1, 2, 5, 1, 1, 1, 81, 1, 1, 26, 28, 2, 1, 11, 1, 1, 1, 35, 2, 2, 5, 3, 3, 1, 1, 4, 3, 4, 2, 1, 2, 1, 3, 2, 4, 1, 1, 1, 13, 4, 1, 1, 1, 4, 6, 2, 1, 3, 1, 3, 2, 4, 1, 34, 1, 5, 11, 2, 1, 1, 1, 3, 27, 1, 2, 4, 1, 1, 1, 7, 1, 1, 21, 1, 6, 1, 8, 2, 29, 6, 2, 1, 21, 5, 1, 1, 2, 2, 2, 2, 1, 3, 4, 1, 1, 16, 1, 4, 2, 5, 14, 6, 3, 1, 2, 2, 1, 1, 2, 1, 2, 3, 2, 1, 2, 1, 1, 2, 1, 1, 1, 1, 3, 1, 2, 59, 1, 1, 7, 1, 2, 1, 31, 3, 1, 1, 1, 4, 2, 2, 1, 16, 1, 13, 1, 3, 1, 1, 10, 2, 6, 1, 4, 6, 1, 1, 2, 4, 1, 1, 1, 11, 2, 1, 828, 103, 3, 1, 5, 2, 1, 3, 4, 1, 1, 9, 6, 2, 2, 2, 3, 37, 1, 1, 2, 1, 1, 4, 2, 1, 1, 1, 1, 2, 1, 4, 2, 31, 1, 16, 1, 1, 1, 1, 11, 4, 1, 1, 1, 1, 8, 1, 4, 1, 3, 1, 1, 3, 1, 2, 1, 2, 1, 2, 1, 5, 2, 2, 8, 1, 3, 1, 5, 5, 1, 11, 2, 1, 7, 1, 2, 1, 1, 1, 12, 4, 1, 4, 28, 1, 1, 6, 13, 2, 1, 5, 4, 1, 229, 1, 1, 4, 2, 1, 8, 8, 1, 14, 1, 2, 1, 1, 1, 4, 1, 1, 3, 2, 6, 1, 9, 1, 2, 5, 1, 1, 5, 2, 1, 1, 3, 5, 2, 70, 2, 1, 2, 1, 2, 7, 3, 2, 1, 19, 1, 38, 1, 1, 1, 3, 17, 1, 37, 10, 1, 4, 10, 1, 5, 2, 1, 1, 13, 15, 1, 13, 1, 1, 26, 5, 1, 1, 4, 1, 3, 1, 2, 1, 1, 1, 13, 1, 1, 5, 3, 1, 1, 3, 2, 1, 186, 1, 2, 1, 1, 31, 1, 1, 4, 1, 1, 1, 3, 9, 2, 3, 6, 5, 1, 3, 8, 1, 2, 226, 10, 3, 17, 1, 8, 7, 1, 15, 8, 2, 2, 65, 1, 2, 2, 2, 4, 1, 5, 1, 9, 1, 6, 1, 1, 1, 1, 1, 1, 4, 1, 117, 1, 3, 1, 2, 3, 1, 14, 1, 17, 317, 1, 102, 9, 1, 2, 1, 3, 3, 2, 1, 1, 1, 5, 2, 7, 2, 2, 2, 19, 1, 2, 1, 6, 12, 1, 1, 4, 4, 5, 13, 4, 4, 1, 4, 2, 5, 1, 1, 2, 5, 1, 1, 1, 1, 5, 1, 1, 1, 1, 1, 32, 5, 1, 3, 2, 1, 1, 5, 16, 14, 3, 1, 3, 11, 3, 1, 1, 3, 2, 4, 71, 2, 1, 4, 1, 1, 6, 1, 1, 1, 2, 2, 1, 1, 3, 1, 2, 1, 2, 7, 5, 1, 8, 1, 14, 1, 1, 2, 1, 1, 5, 9, 2, 7, 1, 9, 8, 5, 1, 1, 1, 9, 1, 23, 1, 6, 1, 6, 8, 3, 1, 15, 3, 3, 1, 1, 4, 6, 2, 1, 4, 2, 1, 2, 4, 4, 10, 1, 5, 9, 2, 2, 3, 1, 2, 8, 1, 4, 1, 9, 1, 1, 1, 1, 1, 2, 1, 4, 1, 1, 1, 5, 28, 3, 1, 1, 12, 1, 2, 2, 5, 1, 7, 21, 6, 1, 21, 1, 1, 1, 21, 1, 2, 2, 1, 1, 1, 1, 4, 1, 2, 1, 4, 2, 13, 1, 1, 2, 1, 5, 1, 2, 1, 12, 1, 4, 1, 22, 1, 1, 1, 2, 1, 1, 3, 1, 1}, giving these values for u and v:

… as taking one more term in the continued fraction would give a value of v of 801560979 3296621968 9692605115 8943214827 1207903669 7664957421 0954203063 7209349594 4461311437 2045488504 3053234888 4134843483 5852646948 3177002904 2019415683 6672346943 4478240470 9829726144 2475296047 5761181347 0244858853 1657320280 8588995635 7329770301 9665844343 0021056818 2879790475 3505835284 4207124134 8524790665 2874135063 2953816349 8581507243 9098201946 5523343967 0303768465 4789960934 7324639582 1678154042 5025318377 3825862065 1074778209 2698730195 7301730505 7147405585 2117671918 0699624827 7426636411 3679779827 3388284283 3898747281 4737154799 5381580915 8446938466 6788701934 6178126620 6425978210 5929193928 2632671898 5780697561 6201776761 8364758488 5793004657 2558483025 0831792830 7153831393 3260873437 3333839278 0057753186 1032469714 0179631297 3021715922 6691120402 6546579232 6678112373 3463684645 4108158152 3665250055 8342243974 2438510118 7770517464 7293480012 2680084823 5152149729 0666788130 6190483455 7028866863 7794657250 9870610872 0375930137 0266955121 7141772630 5164006140 8819066628 0931444719, which is too large.

We also need to calculate d = floor(c4·v/F + 0.5) = 1571 6000045562 2892464788 1185757740 0951840221 5991629828 4107513926 4970921922 1602622896 8805496729 8115166812 5654429331 8013426644 1932750459 9436505446 7471464875 1043882588 0909239097 9428116721 2203966843 2707336674 4685182228 3892363118 5682227222 7138461890 3296525658 2359323026 4616003876 2919911410 0711271313 5842737850 4201258031 1609103582 4698730372 0968833539 3988085953 2385048777 9513636183 6363261791 4969113695 6186408558 3709397204 5432982981 6002123750 5784950426 8280042574 3884359012 4303287391 1625698073 4632677333 5409555777 6295075352 3147023089 4233294004 6785413446 3869741501 1058917751 6492784372 3357766194 4976405807 7880709163 6904164776 0675180990 4151413281 9707352133 6763268786 7135621615 8296878410 3112049211 9379125861 2770079597 1062630203 0030909127 4191807207 5767413249 1106266196 3364384660 0504902750 2819307311 5644923571 5067981913 9865173339 9098707773 1218209863 9914321391 0405784124 2265966616 1469718367 7826971869 4394278704 9237464882 9393135238 6041617006 5449733483 4344616764 9473877315 4235785329 8654618041 8398214801 3731929843 8018615091 6827272905 8933434556 4386664246 4705021137 6430344894 7234414359 6867974161 2091722276 8871930467 4516535834 6690548112 1982810810 3606101421 6973818280 6643217458 2030322860 5340297287 2884406676 1174624221 8751282940 7005043774 7921425670 0326432209 4076353959 7976545436 5033582664 5600238591 5879218956 5961242817 3123203841 4261562416 9748795565 3791167849 3011894851 9097481750 6870276189 2456384579 5095294808 1446836786 4856146350 3224258379 3839381438 0063252501 9673954031 8104796099 6546491683 1106824105 6946559674 2784599379 7148618256 5831364099 0502207702 3624266338 5949214929 4419274461 3801782751 0834050067 3000996174 5748632880 0340751925 8371060727 0774482066 9360954180 0166118008 8660894467 2434658063 1657982266 2057228932 2260402413 5183443360 4284007020 6747388967 1328505322 1203230126 7056011951 0939832646 0552334292 1433156457 3893528331 6265572130 4279022289

Cubic Polynomial

We now consider the cubic P(x)= v·x3 + (u·F-c1·v)·x2 + (c4·v-d·F+u)·x - d, which we express as: z1·x3 + z2·x2 + z3·x + z4, where:

We need to prove that this cubic has no integer roots r such that r·F+1 is a non-trivial factor of N. Clearly r (if it exists) must lie between 1 and R.

As z1 is > 0 and z4 is < 0, we know that P has at least one real root r1 > 0. This is easily found:

Note that the root is not an integer but actually lies in the interval (r1,r1+1).

To see if P has any more real roots, we examine the quadratic derivative P' of P = 3·z1·x2 + 2·z2·x + z3, which we express in the usual quadratic form as a·x2 + b·x + c

As b2-4·a·c is negative, P' has no real roots. Therefore, P has no turning points and is monotonic, implying that r1 is the only real root of P.

There are no integer roots of P in the interval (1,R), so the proof of primality is complete.