login
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
OFFSET
0,4
COMMENTS
sech(x) = 1/cosh(x).
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
Sequence in context: A186247 A215585 A215682 * A215587 A094897 A252096
KEYWORD
sign
AUTHOR
Michel Lagneau, Aug 20 2012
STATUS
approved