A279234 Denominators of coefficients in expansion of 3/(2 + cos(sqrt(x))).

1, 6, 72, 2160, 362880, 1209600, 1437004800, 784604620800, 188305108992000, 19207121117184000, 1990556188508160000, 10116006549998469120000, 25267129482349117440000, 10888869450418352160768000000, 914665033835141581504512000000

Offset

0,2

Links

Clark Kimberling, Table of n, a(n) for n = 0..1000

Example

(1/1) + (1/6)x + (1/72)x^2 + (1/2160)x^3 - (17/362880)x^4 + ... ; 1/1, 1/6, 1/72, 1/2160, -17/362880, ... = A279232/A279234.

Mathematica

z = 26; CoefficientList[Series[3/(2 + Cos[Sqrt[x]]), {x, 0, z}], x];

Crossrefs

Cf. A279232, A279233.

Sequence in context: A009523 A009793 A259212 * A132878 A006585 A166472

Adjacent sequences: A279231 A279232 A279233 * A279235 A279236 A279237

Keyword

nonn,easy,frac

Author

Clark Kimberling, Dec 08 2016

Status

approved