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A279182
Denominators of coefficients in expansion of 1/(-1 + 2 cos(sqrt(x))).
2
1, 1, 12, 360, 20160, 1814400, 34214400, 3962649600, 10461394944000, 457312407552000, 1216451004088320000, 562000363888803840000, 309914286580039680000, 10612933187542253568000000, 152444172305856930250752000000, 18946632843727932759736320000000
OFFSET
0,3
LINKS
EXAMPLE
1/1 + (1/1)x + (11/12)x^2 + (301/360)x^3 + ... ; 1/1, 1/1, 11/12, 301/360, ... = A279181/A279182.
MATHEMATICA
z = 26; t = CoefficientList[Series[1/(-1 + 2 Cos[Sqrt[x]]), {x, 0, z}], x];
Numerator[t] (* A279181 *)
Denominator[t] (* A279182 *)
CROSSREFS
Cf. A279181.
Sequence in context: A012429 A012631 A327986 * A002674 A012552 A012385
KEYWORD
nonn,easy,frac
AUTHOR
Clark Kimberling, Dec 08 2016
STATUS
approved