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 A116072 #3 Mar 30 2012 18:36:55 %S A116072 1,2,18,200,2870,49392,976668,21697104,532727910,14275220960, %T A116072 413469332276,12845983030608,425442421627132,14941814934855200, %U A116072 554044899080129400,21608731448473756320,883563752144886420870 %N A116072 Central terms of triangle A116071, which equals Pascal's triangle to the matrix power of Pascal's triangle. %F A116072 a(n) = (n+1)*A000108(n)*A000248(n). %o A116072 (PARI) {a(n)=local(X=x+x*O(x^(2*n)),Y=y+y*O(y^n)); (2*n)!*polcoeff(polcoeff(exp(X*(Y+exp(X))),2*n,x),n,y)} %Y A116072 Cf. A000248, A080108, A116071. %K A116072 nonn %O A116072 0,2 %A A116072 _Paul D. Hanna_, Feb 03 2006