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 A118051 #3 May 11 2007 03:00:00
%S A118051 1,24,640,580608,199065600,504627200,2191186722816000,
%T A118051 44497945755648000,255806104666112,15953645581139831685120000,
%U A118051 188420950968830433165312000000,401521614736326656000000
%N A118051 Denominators of coefficients in a series for the inverse of harmonic number H(x).
%H A118051 David W. Cantrell, <a href="http://groups.google.com/group/sci.math/msg/0926db8773d69b81">Inverse of Harmonic Numbers</a>
%e A118051 With InvH(x) being the inverse of H(x), x > 0, an asymptotic series for InvH(x) + 1/2 is u - 1/(24u) + 3/(640u^3) - 1525/(580608u^5) +-... where u = e^(x - g) and g is Euler's gamma constant.
%t A118051 n = 12; coeffs = InverseSeries[Exp[Series[HarmonicNumber[x - 1/2], {x, Infinity, 2n - 1}] - EulerGamma]][[3]]; Table[Denominator[coeffs[[2i - 1]]], {i, 1, n}]
%Y A118051 Numerators given in A118050. See also A002387.
%K A118051 frac,nonn
%O A118051 0,2
%A A118051 David W. Cantrell (DWCantrell(AT)sigmaxi.net), Apr 08 2006