A009791 E.g.f. tanh(sin(sin(x))) (odd powers only).

1, -4, 68, -2584, 171344, -17464448, 2529148352, -493428887168, 124730546544896, -39649824402078720, 15479590269182063616, -7280988095409621465088, 4060943278418110382329856, -2650034901967494261760065536

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..100

Example

tanh(sin(sin(x))) = x - 4/3!*x^3 + 68/5!*x^5 - 2584/7!*x^7 +- ...

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Tanh[Sin[Sin[x]]], {x, 0, nn}], x] Range[0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, Apr 17 2014 *)

Crossrefs

Sequence in context: A302115 A009473 A009520 * A012484 A174809 A363427

Adjacent sequences: A009788 A009789 A009790 * A009792 A009793 A009794

Keyword

sign

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Prior Mathematica program replaced by Harvey P. Dale, Apr 17 2014

Status

approved