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 A108881 #4 Dec 15 2017 17:36:51 %S A108881 290,2430,5012,4680,794,2574,26000,3948,18056,10974 %N A108881 Least positive k such that k * [RSA-2048]^n + 1 is prime, where RSA-2048 is the 617 decimal digit RSA challenge number. %C A108881 Another term is a(16)=6766. All values in the sequence are Fermat and Lucas PRPs except for the first which was proved with ECM. The larger values won't be easily provable until RSA-2048 is factored, which has a prize of $200000 for its factorization. %H A108881 Wikipedia, <a href="http://en.wikipedia.org/wiki/RSA-2048">RSA-2048</a> %Y A108881 Cf. A108375, A108573. %K A108881 more,nonn %O A108881 1,1 %A A108881 _Jason Earls_, Jul 14 2005