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 A128578 #8 Mar 27 2016 03:35:25
%S A128578 1,2,24,580,21420,1068480,67189248,5098406400,453030209280,
%T A128578 46120247659200,5290918350734016,675157532791996800,
%U A128578 94836990558591590400,14538639675855504384000,2415072877848471727687680
%N A128578 Main diagonal of table A128570.
%C A128578 Limit n->infinity (a(n)/n!)^(1/n) = 12.67567... . - _Vaclav Kotesovec_, Mar 19 2016
%H A128578 Vaclav Kotesovec, <a href="/A128578/b128578.txt">Table of n, a(n) for n = 0..350</a>
%o A128578 (PARI) {a(n)=local(A=1+(2*n+1)*x); for(j=0,n,A=1+(2*n+1-j)*x*A^2 +x*O(x^n));polcoeff(A,n)}
%Y A128578 Cf. A128570 (triangle), rows: A128318, A128571, A128572, A128573, A128574, A128575, A128576; A128577 (square of row 0), A128579 (antidiagonal sums).
%K A128578 nonn
%O A128578 0,2
%A A128578 _Paul D. Hanna_, Mar 11 2007