A215683 n-th derivative of sech(x)^tanh(x) at x=0.

1, 0, 0, -3, 0, 30, 90, -588, -5040, 11400, 325080, 336072, -25237080, -126955920, 2273150880, 25210740552, -217110741120, -4985924326080, 16380284725440, 1066531842442752, 1493617498611840, -249776526926340480, -1647997041357152640, 63281386481329443072

Offset

0,4

Comments

sech(x) = 1/cosh(x).

Links

Table of n, a(n) for n=0..23.

Formula

E.g.f.: sech(x)^tanh(x).

Maple

a:= n-> n!* coeff(series(sech(x)^tanh(x), x, n+1), x, n):
seq (a(n), n=0..25);  # Alois P. Heinz, Aug 20 2012

Mathematica

f[x_] := Sech[x]^Tanh[x]; Table[Derivative[n][f][0], {n, 0, 25}]

Crossrefs

Cf. A215588.

Sequence in context: A190963 A296436 A215588 * A215586 A215680 A007415

Adjacent sequences: A215680 A215681 A215682 * A215684 A215685 A215686

Keyword

sign

Author

Michel Lagneau, Aug 20 2012

Status

approved