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 A167753 #4 Aug 10 2015 00:29:58 %S A167753 1,1,0,-1,-1,0,0,1,0,-1,0,0,0,-1,0,0,1,0,0,0,0,1,0,0,0,1,0,0,0,0,0,-1, %T A167753 0,0,0,0,-1,0,0,0,0,0,0,1,0,0,0,0,0,-1 %N A167753 Hankel transform of A167751. %C A167753 The nonzero terms appear to be indexed by ceiling((n+1)^2/4) - 0^n (see A004652). %Y A167753 Cf. A167752. %K A167753 sign %O A167753 0,1 %A A167753 _Paul Barry_, Nov 10 2009