A109572 E.g.f.: x/[1-tan(x)].

0, 1, 2, 6, 32, 200, 1536, 13664, 139264, 1595520, 20316160, 284534272, 4347396096, 71958415360, 1282685272064, 24497477345280, 499058556796928, 10802158189445120, 247567232110952448, 5989035387568652288

Offset: 0

Author

Roger L. Bagula, Jun 27 2005

Keywords

• nonn

Comments

"Bernoulli numbers" for x/[1-tan(x)].

Crossrefs

Cf. A057711.

Programs

Maple

G:=x/(1-tan(x)): Gser:=series(G,x=0,25): 0,seq(n!*coeff(Gser,x^n),n=1..22);

Mathematica

g[x_] = x/(-1 + Tan[x]) h[x_, n_] = Dt[g[x], {x, n}] a[x_] = Table[ -h[x, n], {n, 0, 50}]; b = a[0]

Formula

a(n) ~ n! * 2^(2*n-1)/Pi^n. - Vaclav Kotesovec, Jun 26 2013