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 A067324 #4 Mar 31 2012 13:20:07 %S A067324 2,7,23,76,255,869,3003,10504,37128,132430,476102,1723528,6277505, %T A067324 22988385,84592275,312636240,1159979700,4319218530,16134883410, %U A067324 60452176200,227110782990,855361970034,3228982640478 %N A067324 Third column of triangle A067323. %C A067324 Also third diagonal of triangle A028364. %F A067324 a(n)= A067323(n+2, 2)= C(n+3)-(C(n+2)+C(n+1)), C(n) := A000108(n) (Catalan). %F A067324 G.f.: (c(x)^3)*(1+c(x)), with c(x) g.f. of A000108 (Catalan). %Y A067324 Cf. A000245 (second column). %K A067324 nonn,easy %O A067324 0,1 %A A067324 _Wolfdieter Lang_, Feb 05 2002