A202381 Denominators of coefficients in Taylor series expansion of arcsin(cosec(x)-cotanh(x)).

6, 1296, 145152, 156764160, 893931945984, 46352026828800, 2402889070804992, 5903898446967865344000, 205118300328940693094400, 869939530623090109924245504000, 60506034233897163325451123294208000, 105227885624168979696436736163840000, 5629853769947846827574282979744153600000

Offset

0,1

Links

Table of n, a(n) for n=0..12.

Example

-1/6*x+53/1296*x^3+73/145152*x^5+45137/156764160*x^7+11226497/893931945984*x^9+...

Maple

t1:=arcsin(csc(x)-coth(x));
t2:=series(t1, x, 30);
t3:=seriestolist(t2);
t3:=[seq(t3[2*i], i=1..(nops(t3)-2)/2 )];
t4:=map(numer, t3); t5:=map(denom, t3); lprint(t2);

Mathematica

Take[Denominator[Abs[CoefficientList[Series[ArcSin[Csc[x]-Coth[x]], {x, 0, 30}], x]]], {2, -1, 2}] (* Harvey P. Dale, Dec 31 2011 *)

Crossrefs

Cf. A013538.

Sequence in context: A060706 A052278 A264103 * A067510 A013738 A209590

Adjacent sequences: A202378 A202379 A202380 * A202382 A202383 A202384

Keyword

nonn,frac

Author

N. J. A. Sloane, Dec 18 2011

Status

approved