cp's OEIS Frontend

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.

A296854 Expansion of e.g.f. sinh(x*tan(x/2)) (even powers only).

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%I A296854 #6 Dec 26 2017 18:05:42
%S A296854 0,1,1,18,227,4565,126648,4620805,213569269,12165013026,835868220455,
%T A296854 68093897815361,6483538063860336,712877916658802713,
%U A296854 89586864207214060057,12753583150716684461970,2040805972702652020364603,364567588100855831300341565
%N A296854 Expansion of e.g.f. sinh(x*tan(x/2)) (even powers only).
%F A296854 a(n) = (2*n)! * [x^(2*n)] sinh(x*tan(x/2)).
%e A296854 sinh(x*tan(x/2)) = x^2/2! + x^4/4! + 18*x^6/6! + 227*x^8/8! + 4565*x^10/10! + ...
%t A296854 nmax = 17; Table[(CoefficientList[Series[Sinh[x Tan[x/2]], {x, 0, 2 nmax}], x] Range[0, 2 nmax]!)[[n]], {n, 1, 2 nmax + 1, 2}]
%Y A296854 Cf. A001469, A003717, A009611, A110501, A296839, A296841, A296842, A296853, A296856.
%K A296854 nonn
%O A296854 0,4
%A A296854 _Ilya Gutkovskiy_, Dec 21 2017