A012657 E.g.f.: sec(tanh(x)*log(x+1))=1+12/4!*x^4-60/5!*x^5+90/6!*x^6-420/7!*x^7...

1, 0, 0, 0, 12, -60, 90, -420, 19040, -245952, 1660680, -12025200, 266431176, -5435780064, 74009711776, -910402889760, 17440536006400, -420186078195584, 8609810161550016, -157606804730862720

Offset

0,5

Links

Table of n, a(n) for n=0..19.

Mathematica

With[{nn=20}, CoefficientList[Series[Sec[Tanh[x]Log[x+1]], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Jun 03 2014 *)

Crossrefs

Sequence in context: A012400 A009172 A012405 * A012406 A097191 A338159

Adjacent sequences: A012654 A012655 A012656 * A012658 A012659 A012660

Keyword

sign

Author

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

Extensions

Definition clarified by Harvey P. Dale, Jun 03 2014

Status

approved