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 A067306 #6 Feb 10 2014 01:19:58 %S A067306 1,8,75,796,9176,111936,1421968,18618560,249542400,3407171584, %T A067306 47226230528,662805371904,9400304896000,134517761982464, %U A067306 1939837469085696,28162286932246528,411276783645753344 %N A067306 One-fourth of third column of triangle A067304. %F A067306 a(n)= A067304(n+2, 2)/4 = (A067297(n+2) - (A064340(n+2)+A064340(n+1)))/4, n>=0. %F A067306 G.f.: (3+10c(4*x)+3*c(4*x)^2)*(c(4*x)^3)/(1+c(4*x))^4, with c(x) g.f. of A000108 (Catalan). %K A067306 nonn,easy %O A067306 0,2 %A A067306 _Wolfdieter Lang_, Feb 05 2002