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 A123374 #10 Aug 09 2017 22:09:43
%S A123374 2,5,17,151
%N A123374 Primes p such that p^2 divides A086787(p+1).
%C A123374 p divides A086787(p+1) for all prime p, except p=3.
%C A123374 Primes p such that p^2 divides (3 + Sum_{j=1..p+1} B_j) * p + 1, where B_j is the j-th Bernoulli number. [_Max Alekseyev_, Feb 19 2011]
%C A123374 Next term, if it exists, exceeds 320000. [_Max Alekseyev_, Mar 13 2011]
%e A123374 a(1) = 2 because 2^2 divides A086787(3) = 56.
%e A123374 a(2) = 5 because 5^2 divides A086787(6) = 82200, but 3^2 does not divide A086787(4) = 494.
%Y A123374 Cf. A086787.
%K A123374 hard,more,nonn
%O A123374 1,1
%A A123374 _Alexander Adamchuk_, Oct 13 2006