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A279238
Numerators of coefficients in expansion of (cos x)/(1 + cos(sqrt(x))).
3
1, 1, -11, -343, 871, 54871, -12359, -102902159, -137687549, 344971369, 20000206271, -34379966953693, -452834430450401, 18163626705916771, 951418549566510481, -381881231033010506527, -4252976361755938012709, -218740547087902859463611
OFFSET
0,3
LINKS
EXAMPLE
(1/2) + (1/8)x - (11/48)x^2 - (343/5760)x^3 + ... ; 1/2, 1/3, -11/48, 1/6480, -343/5760, ... = A279238/A279239.
MATHEMATICA
z = 26; t = CoefficientList[Series[Cos[x]/(1 + Cos[Sqrt[x]]), {x, 0, z}], x];
Numerator[t] (* A279238 *)
Denominator[t] (* A279239 *)
%/2 (* A279240 *)
CROSSREFS
Sequence in context: A327943 A277348 A033517 * A192841 A158788 A012220
KEYWORD
sign,easy,frac
AUTHOR
Clark Kimberling, Dec 08 2016
STATUS
approved