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 A100867 #11 Aug 09 2015 23:54:36 %S A100867 3,4,3,4,4,3,4,3,5,5,3,4,3,4,4,3,8,4,3,7,3,4,5,3,4,4,3,5,4,3,5,3,4,7, %T A100867 3,4,4,3,7,4,3,5,3,4,5,3,4,4,3,5,4,3,9,7,3,4,3,4,4,3,7,4,3,5,5,3,4,7, %U A100867 3,4,4,3,4,3,9,8,3,4,5,3,4,4,3,5,4,3,7,5,3,4,3,4,4,3,9,4,3,5,8,3,4,5,3,4,4 %N A100867 Smallest positive integer k such that A000037(n) is not a quadratic residue modulo k. %C A100867 The nonzero terms of A139401. %F A100867 a(n) = A139401(A000037(n)). %e A100867 a(1) = 3 because the first nonsquare positive integer is 2 and 2 is not a quadratic residue modulo 3. %K A100867 nonn %O A100867 1,1 %A A100867 Guilherme de Queiroz Hobbs (guilhermehobbs(AT)uol.com.br), Jan 08 2005 %E A100867 Corrected and extended by _David Wasserman_, Mar 04 2008 %E A100867 Edited by _Max Alekseyev_, May 11 2010