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 A000775 #19 Jun 21 2015 17:06:34
%S A000775 1,4,12,46,220,1268,8568,66456,582048,5681952,61174080,720089280,
%T A000775 9199906560,126783809280,1874605662720,29601115891200,497155992883200,
%U A000775 8849184886886400,166399076525875200,3296032301811916800,68596838245232640000,1496490349337948160000
%N A000775 a(n) = n! * (n + 1 + 2*Sum_{k=1...n} 1/k).
%H A000775 T. D. Noe, <a href="/A000775/b000775.txt">Table of n, a(n) for n = 0..100</a>
%H A000775 J. R. Stembridge, <a href="http://dx.doi.org/10.1090/S0002-9947-97-01805-9">Some combinatorial aspects of reduced words in finite Coxeter groups</a>, Trans. Amer. Math. Soc. 349 (1997), no. 4, 1285-1332.
%F A000775 E.g.f.: x/(1-x)+log(1-x)^2. - _Vladeta Jovovic_, Feb 02 2003
%F A000775 a(0)=1, a(n+1) = (n+1)*a(n) + (n+3)*n! for n > 0. - _Sean A. Irvine_, Jun 10 2011
%t A000775 Table[n! (n + 1 + 2*Sum[1/k, {k, n}]), {n, 0, 20}] (* _T. D. Noe_, Jun 20 2012 *)
%Y A000775 Similar to A000774.
%K A000775 nonn
%O A000775 0,2
%A A000775 _N. J. A. Sloane_
%E A000775 Incorrect formula deleted by _Mark van Hoeij_, Nov 11 2009