A013249 Expansion of e.g.f. arctan(log(x+1) - arctan(x)).

0, 0, -1, 4, -6, 0, -90, 600, 6440, -96320, 282240, -28800, 63518400, -658944000, -11371279920, 255692673600, -859133808000, 9642264652800, -1104139083715200, 14885344037491200, 258279234868512000

Offset

0,4

Links

Table of n, a(n) for n=0..20.

Example

-1/2!*x^2 + 4/3!*x^3 - 6/4!*x^4 - 90/6!*x^6 ...

Mathematica

With[{nn=20}, Drop[CoefficientList[Series[ArcTan[Log[x+1]-ArcTan[x]], {x, 0, nn}], x] Range[0, nn]!, 2]] (* Harvey P. Dale, Jun 17 2013 *)

Crossrefs

Sequence in context: A268437 A265685 A111828 * A013253 A013246 A013252

Adjacent sequences: A013246 A013247 A013248 * A013250 A013251 A013252

Keyword

sign

Author

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

Extensions

Definition clarified by Harvey P. Dale, Jun 17 2013

a(0)=a(1)=0 inserted and title improved by Sean A. Irvine, Aug 02 2018

Status

approved