A013477 Coefficient of [x^(4*n+2)] in expansion of e.g.f. tanh(cos(x) - cosh(x)).

-2, 238, -473762, 4544139598, -133366253033282, 9357776691549409198, -1341930712996828590536162, 352757692963898925496158362638, -156922931120424993062032606256707202, 111108598565238227067101723645812683396718

Offset

0,1

Links

Table of n, a(n) for n=0..9.

Example

-2/2!*x^2 + 238/6!*x^6 - 473762/10!*x^10 + 4544139598/14!*x^14 ...

Mathematica

With[{nn=38}, Take[CoefficientList[Series[Tanh[Cos[x]-Cosh[x]], {x, 0, nn}], x] Range[0, nn]!, {3, -1, 4}]] (* Harvey P. Dale, Jul 20 2024 *)

Crossrefs

Sequence in context: A124046 A101146 A159280 * A013473 A212839 A225784

Adjacent sequences: A013474 A013475 A013476 * A013478 A013479 A013480

Keyword

sign

Author

Patrick Demichel (patrick.demichel(AT)hp.com)

Extensions

Missing a(0)=-2 inserted, more terms, and title improved by Sean A. Irvine, Aug 07 2018

Status

approved