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 A186196 #8 Aug 03 2014 14:27:19
%S A186196 1,-1,-6,40,704,-21504,-1409024,178257920,45902462976,-23433341566976,
%T A186196 -24030926136672256,49179307930885816320,201512232261203141853184,
%U A186196 -1650485975228872480767606784,-27044038098228417485446267797504
%N A186196 a(n)=(-1)^n*(-2)^C(n,2)*A001045(n+1).
%C A186196 Hankel transform of A186195.
%t A186196 f[k_] := (2^(k - 1)) (-1)^(k + 1)
%t A186196 t[n_] := Table[f[k], {k, 1, n}]
%t A186196 a[n_] := SymmetricPolynomial[n - 1, t[n]]
%t A186196 Table[a[n], {n, 1, 22}] (* A186196 signed *)
%t A186196 (* _Clark Kimberling_, Dec 30 2011 *)
%K A186196 sign,easy
%O A186196 0,3
%A A186196 _Paul Barry_, Feb 14 2011