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 A134093 #3 Mar 30 2012 18:37:07
%S A134093 1,4,30,215,1729,15176,143814,1462995,15876410,182811992,2223580281,
%T A134093 28458251185,381943459065,5359649816728,78430018675440,
%U A134093 1194057733357517,18873870914263424,309154787519651284,5238840625331179517
%N A134093 Column 3 of triangle A134090.
%C A134093 Row n of triangle T=A134090 = row n of (I + D*C)^n for n>=0 where C denotes Pascal's triangle, I the identity matrix and D a matrix where D(n+1,n)=1 and zeros elsewhere.
%F A134093 a(n) = [x^n] Sum_{k=0..n+3} C(n+3,k)*x^k/(1-k*x)^3 / [Product_{i=1..k}(1-i*x)].
%o A134093 (PARI) {a(n)= polcoeff(sum(k=0,n+3,binomial(n+3,k)*x^k/(1-k*x)^3/prod(i=0,k,1-i*x +x*O(x^n))),n)}
%Y A134093 Cf. A134090; columns: A122455, A134091, A134092; A134094 (row sums); A048993 (S2).
%K A134093 nonn
%O A134093 0,2
%A A134093 _Paul D. Hanna_, Oct 08 2007