A215677 2n-th derivative of sech(x)^cosh(x) at x=0.

1, -1, -1, 44, -211, -9136, 118799, 9894884, -368001271, -3949758496, -1062959453221, 352302017500124, -54987975498787651, 11177493084346370144, -3145848334837840227961, 988952736939184411495964, -349477151478120199840810351, 141758901275895434356815281984

Offset

0,4

Comments

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

The sequence gives only 2n-th derivatives because (2n+1)-th derivatives are 0.

Links

Table of n, a(n) for n=0..17.

Formula

a(n) = (2n)! * [x^(2n)] sech(x)^cosh(x).

Maple

a:= n-> (2*n)!* coeff(series(sech(x)^cosh(x), x, 2*n+1), x, 2*n):
seq(a(n), n=0..20); #  Alois P. Heinz, Aug 20 2012

Mathematica

f[x_] := Sech[x]^Cosh[x]; Table[Derivative[2*n][f][0], {n, 0, 17}]

Crossrefs

Cf. A186248.

Sequence in context: A026908 A183246 A186248 * A122235 A250454 A250447

Adjacent sequences: A215674 A215675 A215676 * A215678 A215679 A215680

Keyword

sign

Author

Michel Lagneau, Aug 20 2012

Status

approved