A009755 Expansion of e.g.f. tan(x)/cos(sin(x)), odd powers only.

1, 5, 41, 517, 12145, 582405, 42317081, 3759817029, 398983432289, 52888501801733, 8949712747169929, 1870731232726437509, 461089997723562652881, 130976488217164121240069, 42778996119131902973150329, 16067412656453434757397261253, 6888568425518076742074506305217

Offset

0,2

Links

G. C. Greubel, Table of n, a(n) for n = 0..240

Maple

a:= n-> (t-> t!*coeff(series(tan(x)/cos(sin(x)), x, t+1), x, t))(2*n+1):
seq(a(n), n=0..17);  # Alois P. Heinz, Feb 15 2018

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Tan[x]/Cos[Sin[x]], {x, 0, nn}], x] Range[0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, Mar 20 2015 *)

Prog

(PARI) x='x+O('x^50); v=Vec(serlaplace(tan(x)/cos(sin(x)))); vector((#v-1)\2 , n, v[2*n-1]) \\ G. C. Greubel, Feb 12 2018

Crossrefs

Sequence in context: A325888 A347951 A275787 * A000685 A144286 A246760

Adjacent sequences: A009752 A009753 A009754 * A009756 A009757 A009758

Keyword

nonn

Author

R. H. Hardin

Extensions

Extended and signs tested by Olivier Gérard, Mar 15 1997

One additional term from and prior Mathematica program replaced by Harvey P. Dale, Mar 20 2015

Status

approved