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 A098087 #5 Mar 30 2012 16:50:02
%S A098087 1,1,5,1,1,-1,-1,1,1,-1,-1,1,691,-691,-1,2,3617,-3617,-43867,43867,
%T A098087 174611,-174611,-77683,155366,236364091,-236364091,-657931,1315862,
%U A098087 3392780147,-6785560294,-3446336510402,6892673020804,7709321041217,-7709321041217,-151628697551,151628697551
%N A098087 Numerators of coefficients in expansion of x^2*(1-exp(-2*x))^(-2).
%C A098087 Suggested by Bill Gosper's remarkable identity (in a posting to math-fun list, Apr 14 2005) (replace dots by spaces to make this more visible): Product_{ n >= 0 } tanh(2^n x)^(1/2^n) = (1-exp(-2*x))^2.
%Y A098087 Cf. A104007, A104042, A104097.
%K A098087 sign,frac
%O A098087 0,3
%A A098087 _N. J. A. Sloane_, Apr 17 2005