A013420 sec(arcsin(x)-arcsinh(x))=1+40/6!*x^6+108000/10!*x^10+1232000/12!*x^12...

1, 0, 0, 40, 0, 108000, 1232000, 1647734400, 57657600000, 85927162048000, 6053574009600000, 11452742596189440000, 1349295190949488640000, 3261229190521061760000000, 577775664177165642240000000

Offset

0,4

Links

Table of n, a(n) for n=0..14.

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Sec[ArcSin[x]-ArcSinh[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, May 05 2021 *)

Crossrefs

Sequence in context: A013373 A013375 A013419 * A156917 A176644 A329337

Adjacent sequences: A013417 A013418 A013419 * A013421 A013422 A013423

Keyword

nonn

Author

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

Status

approved