This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A108375 #6 Apr 03 2023 10:36:10 %S A108375 356,810,1364,1188,1490,4178,164,11312,26,4058,11234,3398,278,4530, %T A108375 2804,7248,14544,942,3504,4704,21194,2708,14636,3222,6990,948,48260, %U A108375 4974,6636,10646,12062,4944,28296,7302,89264,2814,35396,8688,19166,18744 %N A108375 Least positive k such that k * [RSA-200]^n - 1 is prime, where RSA-200 is defined in the Wikinews link. %C A108375 Another term is a(51)=854. All values have been proved prime. Primality proof for a(51), which has 10175 digits: PFGW Version 1.2.0 for Windows [FFT v23.8] Primality testing 854*(279978 ... [digits deleted] ... 823983)^51-1 [N+1, Brillhart-Lehmer-Selfridge] Reading factors from helper file help.txt Running N+1 test using discriminant 5, base 4+sqrt(5) Calling Brillhart-Lehmer-Selfridge with factored part 50.07% 854*(279978 ... [digits deleted] ... 823983)^51-1 is prime! (68.4205s+0.0510s) ======== Also, the Primeform e-group found 25987968300*[RSA-200]^512-1 and 49334180280*[RSA-200]^512-1, each with 102128 digits (see link). %H A108375 Chris Caldwell, <a href="https://t5k.org/bios/page.php?id=339">Primeform e-group bio</a>. %H A108375 Wikinews, <a href="http://en.wikinews.org/wiki/200_digit_number_factored">200 Digit Number Factored</a>. %K A108375 nonn %O A108375 1,1 %A A108375 _Jason Earls_, Jul 02 2005 %E A108375 a(12)-a(40) from _Max Alekseyev_, Feb 02 2010