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 A218718 #4 Nov 05 2012 12:20:11
%S A218718 0,34,3861,344464,20099637,2153335831,102666405913,4867146503697,
%T A218718 923990886302412,50251663587824641,5655954122907587985,
%U A218718 909925832091926912414,85120439454684773642745,2631773999763198769695986,41332517834853462204330752
%N A218718 a(n) is smallest number such that a(n)^2 + 1 is divisible by 89^n.
%e A218718 a(3) = 344464 because 344464^2+1 = 37 * 89 ^ 3 * 4549.
%t A218718 b=34;n89=89;jo=Join[{0,b},Table[n89=89*n89;b=PowerMod[b, 89,n89];b=Min[b,n89-b],{99}]]
%Y A218718 Cf. A002522, A049532, A034939, A218709, A218710, A218712, A218713, A218714, A218715, A218716, A218717.
%K A218718 nonn
%O A218718 0,2
%A A218718 _Michel Lagneau_, Nov 04 2012