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 A106347 #2 Mar 30 2012 18:59:07 %S A106347 1,-1,2,-1,0,0,2,-1,0,0,0,0,0,0,2,-1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,-1, %T A106347 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,-1,0,0, %U A106347 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 %N A106347 A generalized Fredholm-Rueppel sequence. %C A106347 Apply the matrix A106346 to the sequence (-1)^n. %Y A106347 Cf. A036987. %K A106347 easy,sign %O A106347 0,3 %A A106347 _Paul Barry_, Apr 29 2005