A012626 arctan(arcsinh(x)*arctan(x))=2/2!*x^2-12/4!*x^4-2/6!*x^6+10248/8!*x^8...

0, 2, -12, -2, 10248, -672678, -20843460, 16777261590, -2958597356400, -195442688499150, 352062527506877700, -110808084056350289490, -28855116263423436192360, 55915766816627672060266890

Offset

0,2

Links

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

Mathematica

With[{nn=30}, Take[CoefficientList[Series[ArcTan[ArcSinh[x]*ArcTan[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Ray Chandler, Nov 28 2016 *)

Crossrefs

Sequence in context: A128268 A185633 A246737 * A012629 A371589 A082827

Adjacent sequences: A012623 A012624 A012625 * A012627 A012628 A012629

Keyword

sign

Author

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

Status

approved