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 A117336 #3 Mar 30 2012 18:36:56
%S A117336 0,1,-1,6,-27,164,-1133,8930,-78739,768276,-8221025,95775678,
%T A117336 -1207356591,16381797128,-238127430413,3693030808322,-60880099651291,
%U A117336 1063264668030924,-19614400226382041,381146295159812646,-7782393142569110535,166592263396576831760
%N A117336 Column 1 of triangle A117335.
%F A117336 a(n) = Sum_{k=0..n} (-1)^(k+1)*A104981(k).
%o A117336 (PARI) {a(n)=if(n<1,0,(vector(n+1,k,(-1)^k)*matrix(n+1,n+1,m,j,if(m==j,1,if(m==j+1,-m+1, -polcoeff((1-1/sum(i=0,m,i!*x^i))/x+O(x^m),m-j-1))))^-1)[2])}
%Y A117336 Cf. A104981, A117335 (triangle), A117337 (column 2), A117338 (row sums).
%K A117336 sign
%O A117336 0,4
%A A117336 _Paul D. Hanna_, Mar 09 2006