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 A086624 #3 Mar 30 2012 18:36:38 %S A086624 1,1,4,19,100,570,3442,21685,141112,941990,6419174,44493000,312818326, %T A086624 2226155632,16008452202,116167346499,849724397580,6259403310366, %U A086624 46399703925202,345894094030552 %N A086624 Main diagonal of square table A086623 of coefficients of f(x,y) that satisfies f(x,y) = (1-xy)/[(1-x)(1-y)] + xy*f(x,y)^2. %Y A086624 Cf. A086623 (table), A086625 (antidiagonal sums). %K A086624 nonn %O A086624 0,3 %A A086624 _Paul D. Hanna_, Jul 24 2003