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 A103996 #10 May 06 2015 11:54:21
%S A103996 1,-1,2,-9,74,-955,17744,-448077,14751974,-613569711,31452344252,
%T A103996 -1947832408225,143356013568338,-12366684481981635,
%U A103996 1235842203066704648,-141628365906835323573,18449654196553852968254
%N A103996 Recurrence: a(n) = -Sum[i=0..n-1, a(i)*C(n+1,i) ], a(0)=1.
%H A103996 Vaclav Kotesovec, <a href="/A103996/b103996.txt">Table of n, a(n) for n = 0..268</a>
%F A103996 a(n) ~ (-1)^n * c * n^(2*n+4/3) / (2^n * exp(2*n)), where c = 6.48036478570177035603430551468143689346603193431525230833621534239220049... . - _Vaclav Kotesovec_, May 06 2015
%t A103996 nmax = 30; aa = ConstantArray[0,nmax+1]; aa[[1]] = 1; Do[aa[[n+1]]=-Sum[Binomial[n+1,k]*aa[[k+1]],{k,0,n-1}],{n,1,nmax}]; aa (* _Vaclav Kotesovec_, May 06 2015 *)
%Y A103996 Cf. A256006.
%K A103996 sign
%O A103996 0,3
%A A103996 _Ralf Stephan_, Feb 24 2005
%E A103996 Offset changed to 0 by _Vaclav Kotesovec_, May 06 2015