A296544 Expansion of e.g.f. sech(exp(x)-1).

1, 0, -1, -3, -2, 35, 233, 406, -6463, -72951, -234204, 3454165, 59129541, 299098488, -3983040037, -98320221991, -717243756890, 8306677424447, 290745526287213, 2888789037885782, -27716446593438731, -1389236305462658939, -18071746125863480076, 133495439954224143065, 10011730596035533451801

Offset: 0

Author

Ilya Gutkovskiy, Dec 15 2017

Keywords

• sign

Examples

			sech(exp(x)-1) = 1 - x^2/2! - 3*x^3/3! - 2*x^4/4! + 35*x^5/5! + 233*x^6/6! + ...
		

Crossrefs

Cf. A000364, A024430, A139134, A296543.

Programs

Maple

a:=series(sech(exp(x)-1),x=0,25): seq(n!*coeff(a,x,n),n=0..24); # Paolo P. Lava, Mar 27 2019

Mathematica

nmax = 24; CoefficientList[Series[Sech[Exp[x] - 1], {x, 0, nmax}], x] Range[0, nmax]!

Formula

E.g.f. 1/cosh(exp(x)-1).