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 A145871 #3 Mar 30 2012 17:27:56
%S A145871 32318,6826318,96940388,7986582530,24900904028,92615568742,
%T A145871 416081467190,988322434636,3219884218827,4867146503697,26457926739667,
%U A145871 47023298541694,26661771973542,90980209992989,257680081342861,283410689912607
%N A145871 Smallest k such that k^2+1 is divisible by A002144(n)^7.
%e A145871 a(2) = 6826318 since A002144(2) = 13, 6826318^2+1 = 46598617437125 = 5^3*13^7*13*457 and for no k < 6826318 does 13^7 divide k^2+1. a(4) = 7986582530 since A002144(4) = 29, 7986582530^2+1 = 63785500508501200901 = 29^7*197*409*45893 and for no k < 7986582530 does 29^7 divide k^2+1.
%o A145871 (PARI) {e=7; forprime(p=2, 40, if(p%4==1, q=p^e; m=q; while(!issquare(m-1, &n), m=m+q); print1(n, ",")))}
%Y A145871 Cf. A002144 (primes of form 4n+1), A002313 (-1 is a square mod p), A059321, A145296, A145297, A145298, A145299, A145872, A145873.
%K A145871 nonn
%O A145871 1,1
%A A145871 _Klaus Brockhaus_, Oct 22 2008
%E A145871 More terms from _Klaus Brockhaus_, Nov 12 2008