login
A279235
Numerators of coefficients in expansion of 1/(2 - cos(sqrt(x))).
2
1, -1, 7, -121, 3907, -28963, 15430207, -1619195761, 415698113, -39531606447181, 787393078729637, -329597897026412143, 56485166839707031039, -25018119236152953236111, 17136704858994825564634201, -5470262193930829308041366531, 34416659770990341862308561437707
OFFSET
0,3
LINKS
EXAMPLE
(1/1) - (1/2)x + (7/24)x^2 - (121/720)x^3 + ... ; 1/1, -1/2, 7/24, 1/6480, -121/720, ... = A279235/A279236.
MATHEMATICA
z = 26; t = CoefficientList[Series[1/(2 - Cos[Sqrt[x]]), {x, 0, z}], x];
Numerator[t] (* A279235 *)
Denominator[t] (* A279236 *)
CROSSREFS
Cf. A279236.
Sequence in context: A113267 A274267 A012028 * A094088 A012043 A316730
KEYWORD
sign,easy,frac
AUTHOR
Clark Kimberling, Dec 08 2016
STATUS
approved