A091197 Denominators of Taylor series expansion of 3*sin(2*x)/(2*(2+cos(2*x))) (with 0's omitted).

1, 1, 45, 189, 405, 31185, 1658475, 4209975, 97692469875, 65511420975, 4396161144375, 1613742832877175, 1447106344699640625, 316985199315159375, 790515124238106783140625, 845033408668321044046875, 1693960980510228821015625, 84913182070036240111050234375

Offset

0,3

References

G. H. Hardy, A Course of Pure Mathematics, 9th ed., 1944, p. 291.

Links

Table of n, a(n) for n=0..17.

G. H. Hardy, A Course of Pure Mathematics, Cambridge, The University Press, 1908.

Example

3*sin(2*x)/(2*(2+cos(2*x))) = x-4/45*x^5-8/189*x^7-4/405*x^9+8/31185*x^11+...

Mathematica

Join[{1, 1}, Take[CoefficientList[Series[3Sin[2x]/(2(2+Cos[2x])), {x, 0, 40}], x], {6, -1, 2}]//Denominator] (* Harvey P. Dale, May 25 2024 *)

Crossrefs

Cf. A091198.

Sequence in context: A280887 A158630 A158634 * A184539 A146302 A203835

Adjacent sequences: A091194 A091195 A091196 * A091198 A091199 A091200

Keyword

nonn,frac

Author

N. J. A. Sloane, Feb 23 2004

Status

approved