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 A218713 #4 Nov 05 2012 12:18:55
%S A218713 0,6,117,9466,800982,6423465,756360062,24900904028,1019349744435,
%T A218713 15069267560119,794839706330581,71333925879937154,2419512779032508628,
%U A218713 116073623326088126430,359642847542169431827,144552623583462302226851,3523356323886506075746572
%N A218713 a(n) is smallest number such that a(n)^2 + 1 is divisible by 37^n.
%e A218713 a(3) = 9466 because 9466^2+1 = 29 * 37 ^ 3 * 61.
%t A218713 b=6;n37=37;jo=Join[{0,b},Table[n37=37*n37;b=PowerMod[b,37,n37];b=Min[b,n37-b],{99}]]
%Y A218713 Cf. A002522, A049532, A034939, A218709, A218710, A218712.
%K A218713 nonn
%O A218713 0,2
%A A218713 _Michel Lagneau_, Nov 04 2012