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 A071936 #5 Mar 30 2012 18:39:03 %S A071936 1,-1,1,1,1,1,1,1,1,-1,1,1,1,1,1,1,1,-1,1,1,1,1,1,1,1,-1,1,1,1,1,1,1, %T A071936 1,-1,1,1,1,1,1,1,1,-1,1,1,1,1,1,1,1,-1,1,1,1,1,1,1,1,-1,1,1,1,1,1,1, %U A071936 1,-1,1,1,1,1,1,1,1,-1,1,1,1,1,1,1,1,-1,1,1,1,1,1,1,1,-1,1,1,1,1,1,1,1,-1,1,1,1,1,1,1,1,-1,1,1,1,1,1,1,1,-1,1,1,1,1,1,1 %N A071936 K(n+1,n) where K(x,y) is the Kronecker symbol (x/y). %F A071936 If n==2 (mod(8)) a(n)=-1 a(n)=1 otherwise %o A071936 (PARI) for(n=1,150,print1(kronecker(n+1,n),",")) %K A071936 easy,sign %O A071936 1,1 %A A071936 _Benoit Cloitre_, Jun 14 2002