login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A279311 Denominators of coefficients in expansion of (cos x)/(1 - x - x^2). 2
1, 1, 2, 2, 24, 24, 720, 720, 4480, 40320, 3628800, 3628800, 479001600, 95800320, 2641766400, 87178291200, 1902071808000, 20922789888000, 6402373705728000, 6402373705728000, 810967336058880000, 143111882833920000, 66117689869271040000, 13223537973854208000 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

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

EXAMPLE

(1/1) + (1/1)x + (3/2)x^2 + (5/2)x^3 + ... ; 1/1, 1/1, 3/2, 5/2, ... = A279310/A279311.

MATHEMATICA

z = 30; t =  CoefficientList[Series[Cos[x]/(1 - x - x^2), {x, 0, z}], x];

Numerator[t]   (* A279310 *)

Denominator[t] (* A279311 *)

CROSSREFS

Cf. A279310.

Sequence in context: A120065 A250033 A224479 * A248812 A226243 A226979

Adjacent sequences:  A279308 A279309 A279310 * A279312 A279313 A279314

KEYWORD

nonn,easy,frac

AUTHOR

Clark Kimberling, Dec 11 2016

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 6 16:29 EDT 2020. Contains 334828 sequences. (Running on oeis4.)