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A122509 Expansion of x/(1 - 2*x^2 - 21*x^3). 1
0, 1, 0, 2, 21, 4, 84, 449, 252, 2662, 9933, 10616, 75768, 229825, 374472, 2050778, 5575269, 11965468, 54216876, 141011585, 359708580, 1420577566, 3680660445, 10395035312, 37193449776, 98083939969, 292682641104, 977230325234 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,4
LINKS
FORMULA
G.f.: x/(1 - 2*x^2 - 21*x^3).
MATHEMATICA
CoefficientList[Series[x/(1 -2*x^2 -21*x^3), {x, 0, 30}], x]
PROG
(Magma) I:=[0, 1, 0]; [n le 3 select I[n] else 2*Self(n-2) +21*Self(n-3): n in [1..31]]; // G. C. Greubel, Jul 11 2021
(Sage)
def A122509_list(prec):
P.<x> = PowerSeriesRing(ZZ, prec)
return P( x/(1 -2*x^2 -21*x^3) ).list()
A122509_list(30) # G. C. Greubel, Jul 11 2021
CROSSREFS
Sequence in context: A162536 A100980 A360980 * A024230 A358520 A105666
KEYWORD
nonn,easy
AUTHOR
Roger L. Bagula, Sep 15 2006
EXTENSIONS
Edited by G. C. Greubel, Jul 11 2021
STATUS
approved

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Last modified June 25 13:13 EDT 2024. Contains 373705 sequences. (Running on oeis4.)