A012831 cosh(sec(x)*arcsinh(x))=1+1/2!*x^2+9/4!*x^4+225/6!*x^6+6993/8!*x^8...

1, 1, 9, 225, 6993, 467745, 29529753, 4297350785, 378759492257, 122599030798017, 8002975063348265, 9354851201922233249, -686072407102337430543, 1787263355638656126843105

Offset

0,3

Links

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

Crossrefs

Sequence in context: A067405 A063386 A063392 * A012749 A188662 A079727

Adjacent sequences: A012828 A012829 A012830 * A012832 A012833 A012834

Keyword

sign

Author

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

Status

approved