A215680 n-th derivative of sec(x)^tan(x) at x=0.

1, 0, 0, 3, 0, 30, 90, 588, 5040, 26520, 325080, 2158728, 27731880, 249259920, 3181258080, 36821629848, 482278043520, 6704476956480, 93675256079040, 1479108131816448, 22566722722104960, 390679249452835200, 6559255213047250560, 122197022127873558528

Offset

0,4

Comments

sec(x) = 1/cos(x).

Links

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

Formula

E.g.f.: sec(x)^tan(x).

Maple

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

Mathematica

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

Crossrefs

Cf. A215586.

Sequence in context: A215588 A215683 A215586 * A007415 A145222 A377309

Adjacent sequences: A215677 A215678 A215679 * A215681 A215682 A215683

Keyword

nonn

Author

Michel Lagneau, Aug 20 2012

Status

approved