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A215681 n-th derivative of sech(x)^tan(x) at x=0. 1
1, 0, 0, -3, 0, -10, 90, -308, 1680, -13560, 123480, -788568, 7646760, -76432720, 841320480, -8436217208, 103473901440, -1320024546240, 17546621595840, -235942960528128, 3481689023521920, -54132188358133120, 858287202343992960, -14187715233218409728 (list; graph; refs; listen; history; text; internal format)
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)^tan(x).

MAPLE

a:= n-> n!* coeff(series(sech(x)^tan(x), x, n+1), x, n):

seq (a(n), n=0..25);  # Alois P. Heinz, Aug 20 2012

MATHEMATICA

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

CROSSREFS

Cf. A215585, A215587.

Sequence in context: A186247 A215585 A215682 * A215587 A094897 A252096

Adjacent sequences:  A215678 A215679 A215680 * A215682 A215683 A215684

KEYWORD

sign

AUTHOR

Michel Lagneau, Aug 20 2012

STATUS

approved

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Last modified September 25 12:12 EDT 2022. Contains 356984 sequences. (Running on oeis4.)