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 A167751 #9 Jan 11 2015 02:03:37 %S A167751 1,0,1,1,2,4,7,14,27,52,102,198,387,755,1474,2879,5622,10982,21450, %T A167751 41900,81847,159880,312315,610086,1191768,2328054,4547732,8883767, %U A167751 17354001,33900200,66222412,129362318,252703135,493643580,964309346 %N A167751 Diagonal sums of A167749. %C A167751 Hankel transform is A167753. %F A167751 G.f.: 1/(1-x^2/(1-x/(1-x^2/(1-x^3/(1-x^4/(1-...)))))) (continued fraction); %F A167751 G.f.: 1/(1-x^2*f(x)), f(x) the g.f. of A005169. %e A167751 G.f. = 1 + x^2 + x^3 + 2*x^4 + 4*x^5 + 7*x^6 + 14*x^7 + 27*x^8 + 52*x^9 + ... %K A167751 easy,nonn %O A167751 0,5 %A A167751 _Paul Barry_, Nov 10 2009