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 A009356 #13 Jun 22 2015 22:20:02
%S A009356 0,1,-3,9,-32,140,-757,4963,-38376,341664,-3438641,38576747,
%T A009356 -477118600,6447914668,-94515392805,1493405394411,-25300960235504,
%U A009356 457490990665952,-8793604786338049,179039287811168755,-3849069823206873888
%N A009356 Expansion of log(1+sinh(x))/exp(x).
%F A009356 a(n) ~ (n-1)! * (-1)^(n+1) * (1+sqrt(2)) / (log(1+sqrt(2)))^n. - _Vaclav Kotesovec_, Jan 23 2015
%t A009356 Log[ 1+Sinh[ x ] ]/Exp[ x ]
%t A009356 CoefficientList[Series[Log[1 + Sinh[x]]/E^x, {x, 0, 20}], x] * Range[0, 20]! (* _Vaclav Kotesovec_, Jan 23 2015 *)
%K A009356 sign,easy
%O A009356 0,3
%A A009356 _R. H. Hardin_
%E A009356 Extended with signs by _Olivier Gérard_, Mar 15 1997