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 A154998 #3 Mar 30 2012 17:27:02
%S A154998 3,2001907169
%N A154998 Primes p such that p^2 divides A048861((p-1)/2).
%C A154998 No other terms below 10^11.
%F A154998 Elements of A125854 congruent to 1 or 3 modulo 8, i.e., primes p such that p == 1 or 3 (mod 8) and 2^(p-1) == 1+p (mod p^2).
%o A154998 (PARI) { forprime(p=3,10^11, if(Mod((p-1)/2,p^2)^((p-1)/2)==1, print(p);)) }
%Y A154998 A048861,A121999,A125854
%K A154998 bref,hard,more,nonn
%O A154998 1,1
%A A154998 _Max Alekseyev_, Jan 18 2009
%E A154998 Edited by _Max Alekseyev_, Oct 13 2009