A294313 Expansion of e.g.f. sech(x*exp(x)).

1, 0, -1, -6, -19, 20, 899, 7966, 27705, -366552, -8374201, -80690302, 9794597, 16015845820, 317370642315, 2554368906150, -37571987331343, -1784464543440304, -31315944840101233, -80221319702865398, 12685422355781995485, 422083364962616527716

Offset

0,4

Links

Table of n, a(n) for n=0..21.

Example

sech(x*exp(x)) = 1 - x^2/2! - 6*x^3/3! - 19*x^4/4! + 20*x^5/5! + 899*x^6/6! + ...

Maple

a:=series(sech(x*exp(x)), x=0, 22): seq(n!*coeff(a, x, n), n=0..21); # Paolo P. Lava, Mar 27 2019

Mathematica

nmax = 21; CoefficientList[Series[Sech[x Exp[x]], {x, 0, nmax}], x] Range[0, nmax]!
nmax = 21; CoefficientList[Series[1/Cosh[x Exp[x]], {x, 0, nmax}], x] Range[0, nmax]!

Crossrefs

Cf. A000364, A009017, A009121, A009301, A009448, A009565, A009635, A009768, A191719, A216401, A217502, A294312, A296544, A297009, A297010.

Sequence in context: A173568 A012589 A009048 * A235537 A046955 A042215

Adjacent sequences: A294310 A294311 A294312 * A294314 A294315 A294316

Keyword

sign

Author

Ilya Gutkovskiy, Dec 27 2017

Status

approved