A013487 cos(cos(x)-sech(x))=1-560/8!*x^8+50400/10!*x^10-4403520/12!*x^12...

1, 0, 0, 0, -560, 50400, -4403520, 451651200, -55603258880, 8098495142400, -1364657183216640, 258905686980864000, -53203592135631564800, 11000355030582368256000, -1812425415209721012879360

Offset

0,5

Links

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

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Cos[Cos[x]-Sech[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Nov 30 2014 *)

Crossrefs

Sequence in context: A196568 A171347 A193171 * A229389 A167822 A104590

Adjacent sequences: A013484 A013485 A013486 * A013488 A013489 A013490

Keyword

sign

Author

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

Status

approved