A012406 Expansion of e.g.f.: sec(arctan(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, 21728, -270144, 1479240, -9807600, 330821832, -6651092448, 71604108576, -744095308320, 20714430198528, -548875353239424, 9233126375705280, -138948347142163584

Offset

0,5

Links

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

Mathematica

With[{nn=20}, CoefficientList[Series[Sec[ArcTan[x]Log[x+1]], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Apr 07 2018 *)

Crossrefs

Sequence in context: A009172 A012405 A012657 * A097191 A338159 A273691

Adjacent sequences: A012403 A012404 A012405 * A012407 A012408 A012409

Keyword

sign

Author

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

Extensions

Definition clarified by Harvey P. Dale, Apr 07 2018

Status

approved