A009042 - OEIS

A009042

Expansion of x*cos(sin(x)), odd terms only.

1, -3, 25, -259, 4113, -89859, 2452905, -82466115, 3364642465, -162289204995, 9080010901689, -582825476943747, 42497355011746225, -3485070555315399171, 318706043315086782281, -32281156967340604488131

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..250

MATHEMATICA

With[{nmax = 62}, CoefficientList[Series[x*Cos[Sin[x]], {x, 0, nmax}], x]*Range[0, nmax - 1]!][[2 ;; ;; 2]] (* G. C. Greubel, Jul 23 2018 *)

PROG

(PARI) x='x+O('x^60); v=Vec(serlaplace(x*cos(sin(x)))); vector((#v-1)\2 , n, v[2*n-1]) \\ G. C. Greubel, Jul 23 2018

CROSSREFS

Sequence in context: A006091 A357232 A355865 * A080896 A126746 A118989

Adjacent sequences: A009039 A009040 A009041 * A009043 A009044 A009045

KEYWORD

sign

AUTHOR

R. H. Hardin

EXTENSIONS

Extended with signs by Olivier Gérard, Mar 15 1997

STATUS

approved