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 A113146 #8 Sep 08 2013 13:30:50
%S A113146 1,1,2,9,83,1226,24727,627909,19169758,682800001,27776711627,
%T A113146 1270110048234,64470498348983,3596569233141701,218698213338646702,
%U A113146 14395754017090902609,1019782749198898131883,77351848007810972904826
%N A113146 Row 5 of table A113143; equal to INVERT of quintic (or 5-fold) factorials shifted one place right.
%F A113146 a(n) = Sum_{j=0..k} 5^(k-j)*A111146(k, j).
%F A113146 a(0) = 1; a(n+1) = Sum_{k=0..n} a(k)*A008548(n-k).
%e A113146 A(x) = 1 + x + 2*x^2 + 9*x^3 + 83*x^4 + 1226*x^5 +...
%e A113146 = 1/(1 - x - x^2 - 6*x^3 - 66*x^4 -...- A008548(n)*x^(n+1)
%e A113146 -...).
%o A113146 (PARI) {a(n)=local(x=X+X*O(X^n)); A=1/(1-x-x^2*sum(j=0,n,x^j*prod(i=0,j,5*i+1)));return(polcoeff(A,n,X))}
%Y A113146 Cf. A113143, A008548 (5-fold factorials).
%K A113146 nonn
%O A113146 0,3
%A A113146 _Philippe Deléham_ and _Paul D. Hanna_, Oct 28 2005