A007451 Denominators of expansion of exp x / sin x.

1, 3, 3, 90, 18, 945, 1890, 12600, 22680, 53460, 1247400, 10216206000, 157172400, 1021620600, 6129723600, 534386160000, 81729648000, 2494674910728000, 127932046704000, 2744142401800800000

Offset

0,2

Links

Robert Israel, Table of n, a(n) for n = 0..70

Maple

c:= proc(m) option remember;
  1/(m+1)! - add((-1)^i/(2*i+1)!*c(m-2*i), i=1..floor((m+1)/2))
end proc;
c(-1):= 1;
A007451:= denom @ c; # Robert Israel, Apr 13 2014

Mathematica

Denominator[CoefficientList[Series[Exp[x]/Sin[x], {x, 0, 20}], x]]//Quiet (* Harvey P. Dale, Mar 16 2018 *)

Crossrefs

Cf. A007418.

Sequence in context: A260076 A024189 A217542 * A087542 A016456 A010266

Adjacent sequences: A007448 A007449 A007450 * A007452 A007453 A007454

Keyword

nonn,frac

Author

N. J. A. Sloane.

Status

approved