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A215682
n-th derivative of sec(x)^tanh(x) at x=0.
0
1, 0, 0, 3, 0, -10, 90, 308, -1680, 1560, 123480, -43032, -5151960, 40323920, 538618080, -3880887592, -32036135040, 815589894720, 4367132072640, -121636569852672, -35223107829120, 29236492773887360, -32794445470765440, -6014518868589379072, 45105535773064694400
OFFSET
0,4
COMMENTS
sec(x) = 1/cos(x).
FORMULA
E.g.f.: sec(x)^tanh(x).
MAPLE
a:= n-> n!* coeff(series(sec(x)^tanh(x), x, n+1), x, n):
seq (a(n), n=0..25); # Alois P. Heinz, Aug 20 2012
MATHEMATICA
f[x_] := Sec[x]^Tanh[x]; Table[Derivative[n] [f][0], {n, 0, 25}]
CROSSREFS
Cf. A215585.
Sequence in context: A215347 A186247 A215585 * A215681 A215587 A094897
KEYWORD
sign
AUTHOR
Michel Lagneau, Aug 20 2012
STATUS
approved