A012544 sech(sinh(x)*arcsin(x))=1-12/4!*x^4-240/6!*x^6+1680/8!*x^8...

1, 0, -12, -240, 1680, 660480, 39530304, -3855231744, -1466146656000, -147651751649280, 43245441015313408, 21785411128189063168, 453349606338812022784, -4374564365537166405795840

Offset

0,3

Links

Table of n, a(n) for n=0..13.

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Sech[Sinh[x]ArcSin[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Jun 03 2023 *)

Crossrefs

Sequence in context: A012351 A189883 A033469 * A009052 A213449 A012303

Adjacent sequences: A012541 A012542 A012543 * A012545 A012546 A012547

Keyword

sign

Author

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

Status

approved