A009548 Expansion of e.g.f. sin(x)*sin(tan(x)) (even powers only).

0, 2, 0, -32, -1984, -118016, -8529920, -754714880, -79868821504, -9749056634880, -1296267479826432, -165153529347768320, -9993013885707223040, 7114872804447958401024, 5975166564856692622753792

Offset

0,2

Links

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

Mathematica

With[{nmax = 50}, CoefficientList[Series[Sin[x]*Sin[Tan[x]], {x, 0, nmax}], x]*Range[0, nmax]!][[1 ;; ;; 2]] (* G. C. Greubel, Jan 20 2018 *)

Prog

(PARI) x='x+O('x^50); v=Vec(serlaplace(sin(x)*sin(tan(x)))); concat([0], vector(#v\2, n, v[2*n-1])) \\ G. C. Greubel, Jan 20 2018

Crossrefs

Sequence in context: A340545 A009665 A053552 * A172388 A193052 A347900

Adjacent sequences: A009545 A009546 A009547 * A009549 A009550 A009551

Keyword

sign,changed

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Status

approved