Primality Certificate for (15679^3499-1)/15678

Andy Steward14,676 digits20 January 2008
Originally by David Broadhurst & Bouk de Water 2003

This certificate uses a theorem of Brillhart, Lehmer and Selfridge 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 35.622981% factorization of N-1:

From Factorisation
1567915679
Φ22 · 2 · 2 · 2 · 2 · 2 · 5 · 7 · 7
Φ33 · 4201 · 19507
Φ697 · 2534179
Φ1123 · 91406600732767 · 427076727834949318967389561
Φ22138337 · 435072602647142021 · 14916118119135592943
Φ33199 · 3037 · 140977 · 14869273 · 5960137883285191 · p51
Φ53107 · 87164543 · p209
Φ66p84
Φ1064877 · 6997 · 2495771 · 17519242514363 · 1415697491214452543 · 103003372673620241811483109 · p147
Φ15934981 · 280581131119 · 20226331972667674284313 · 8760627760529248288064629 · 732214945285216501464215071 · c347
Φ318c437
Φ5832333 · 372774240191 · c2167
Φ1166c2182
Φ17493499 · 1332739 · p4354
Φ3498169093321 · 346202087001776149 · 402840969336893209981 · c4317

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

2900 2348602068 4365561301 2126450597 4852709165 1461399230 7091062308 0796170718 1860348389 6155106377 1534551093 7421027679 9955102610 2336145591 3703614052 8096050114 1352846608 9932640935 3494574131 1521636732 6242110572 6125695424 5666446143 0309341182 9260717378 3939550015 2837538718 6939963862 0474713815 9269609237 2661594979 4601258209 5639840948 7430994411 7842414035 5010628292 4678308647 1634387711 7907140676 7705042631 1627204119 8474588071 6737727904 9662547367 0155746239 2160875822 5336524405 6316571698 3305373542 0900788789 9311744299 8026633821 8810012253 6492161668 6251886559 4284219363 4373185621 3092471451 1403138992 5379083331 7687735443 5586309585 0147859503 8390889196 0945025913 7995044234 3645748247 7052793741 0188159382 2916513268 5113096341 3196574797 2415477111 8479477558 2851386792 4995726415 2978649008 1411479745 8971130873 9950979689 9408901408 7446651354 4839931508 4113739950 8629339535 1337811252 1818321359 5914108127 1033983867 2038823677 4809032496 8652199567 7356100832 2767157971 9778708411 7595720057 2949100187 1484445905 9548489899 7169939126 2163143417 5152738084 6593227936 3074271564 6190779705 2873996285 8504528675 4938088548 5560513100 0998474734 8878146238 4152316169 5124936500 5953547019 5735301467 4851305949 1576102782 7664055027 7053582842 8233297612 1227798100 2031186641 3296457965 2875762797 0938093498 9704985663 5034190391 9993971493 1605918787 4527163391 8103302098 8912173263 8835697041 7118325848 0069559884 2212345714 2614656238 7357898756 4829169369 4254751981 8270692753 2354623827 0315247498 8520587330 7356172908 1361861534 2763538240 3997746025 5917314960 2838304738 3225056357 5650086374 6661978767 0110143057 7414829484 0043126219 6023061273 1310697225 1577125356 5568641516 5012812640 8454051103 3640344459 6399374439 4818927294 7548852548 3401977235 2197742903 9384907156 1635982812 1050391553 9708757280 2465767363 3167026988 2188906455 7022807881 2871157911 0401075843 3957017024 6988946686 3658824219 4573114454 6759446241 1135402126 5400605600 8698780749 1844493088 1017795179 0983821027 9229068064 7577006581 0971972030 5323969546 7774384287 2628728787 7509344645 3922936968 5837938853 7988248308 6585112512 8834881064 3546054043 2526689724 0772384353 8899630628 2055894885 6668253345 4617538423 3528365657 9651670877 2110836240 5405312592 6969449499 2844109259 0978331201 2515270509 6978281123 2967897551 9496198571 1824833817 6054472584 9840793000 5889639923 1191793040 7305692604 3774718758 2598663722 4345148797 6714040597 0442793533 6854247653 4991500888 9457780500 0612383382 8383570522 5819314089 4135344276 7777464232 2363499908 3099819963 4668679674 7713166234 6018340730 4652390963 8784216473 0254630999 1213752030 5332383036 3228278806 6033304858 5717993368 7808420473 3263488988 8375412335 2317152063 3755456338 1227691329 2940542314 0583909944 2570413252 1731957313 8124648268 5117524161 8293290921 9939219326 7166407711 0097163182 4312758652 7114533341 4005493522 8696997257 2131032464 7833140719 5244328770 3478195273 0949278155 8381462890 1798037558 8142431393 8265844248 8609141869 9808446280 0131150355 7556556586 1886650041 3131839563 2679808698 2620154111 9032969502 2802795833 7347917045 2268241456 6704283053 9003993244 9189752796 1952112943 5267208507 2519221213 7857868143 9753952126 1855537972 3271741107 0660182727 9670414748 1332985397 6867378243 2386766345 8286618950 9663508277 9241898488 8513541296 7103693117 2761992121 4690890058 9150821021 8888478880 7216784954 7447650908 5768316721 8274957073 7500313671 8733683936 9886540595 9462523219 6513858901 8021541522 0508623274 6599348849 3464530656 2582040621 6984020459 5978665989 4192362911 5081481321 2381618411 3215092615 1962682604 2612111530 4609463246 6379450961 5008764552 8709562283 2853193788 6857558059 7864394569 8888890959 0543578348 0133651315 5433952158 2367992326 3774361724 0905633266 6545739154 1082625001 9659281995 1338518518 3464930491 7104784019 3709141694 8723605751 4187919872 4658503488 9401333313 4861802043 6556822508 2220941411 1995022286 5318939919 6535552365 5735263715 2477642107 0868133923 2453860176 5932648120 7971553601 8725080853 5458464652 4129679175 0436185773 5997446026 4802870383 2156898995 0066577379 4350276247 5935640283 2768958045 8993936840 0870491907 2238366423 1340749796 8470904231 0795865503 2801850541 5726736637 1385356753 1277280033 3923044367 5788414904 3843003834 3922540276 1023798438 0986417722 3381209203 3178183035 5222582985 0663280971 2942391855 2093005442 0584248079 3814489681 9040136969 1516577962 1850945514 4575804980 0378807103 6085237077 7726704029 8617587530 4015308219 2699897990 4489636096 1179264985 9509503167 1562710433 6334007855 7797021898 1960381517 2705555585 9417339666 4008978817 4669271691 9221818940 5948053326 5896378740 1702525243 9296490241
153765459 6043919472 0127746549 1107336381 1219464673 9432468467 3947197246 9576144345 9264912845 1164977484 4191130347 3683802086 5934037677 1127816244 9245819371 6674294930 3935482402 0720955509 1942290772 9017862683 8353586621
6590531 3761712145 0190295257 1687462317 1385649273 2807257124 6272175960 5402308728 5069433053 9016798087 3760332342 5042651073 5062555021 1832648218 1091630327
8061 1109841722 1911672523 5141141966 0508149382 5576615584 5272637114 1567980249 8015587201
1 0674494733 8847372498 6426333843 0185655351 3388747357
7322149 4528521650 1464215071
4270767 2783494931 8967389561

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) = 33.361659%

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 = 11 suffices.

Given such a witness, Pocklington's Theorem shows that every prime factor of N ≡ 1 (mod F). As F3>N, N can have no more than two prime factors.

Express N in base F

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

Brillhart, Lehmer and Selfridge

Brillhart, Lehmer and Selfridge's Theorem shows that N is prime if and only if c12-4·c2 is not a square (given 2F3 > N).

Here, c12-4·c2 is ≡ 60 (mod 64) and therefore cannot be a square and N is prime.