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A296544 Expansion of e.g.f. sech(exp(x)-1). 2
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

Table of n, a(n) for n=0..24.

FORMULA

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

EXAMPLE

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

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]!

CROSSREFS

Cf. A000364, A024430, A139134, A296543.

Sequence in context: A252595 A292158 A303729 * A136635 A062743 A009084

Adjacent sequences:  A296541 A296542 A296543 * A296545 A296546 A296547

KEYWORD

sign

AUTHOR

Ilya Gutkovskiy, Dec 15 2017

STATUS

approved

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Last modified March 8 11:34 EST 2021. Contains 341948 sequences. (Running on oeis4.)