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A174522
Expansion of 1/(1 - x - x^4 + x^6).
23
1, 1, 1, 1, 2, 3, 3, 3, 4, 6, 7, 7, 8, 11, 14, 15, 16, 20, 26, 30, 32, 37, 47, 57, 63, 70, 85, 105, 121, 134, 156, 191, 227, 256, 291, 348, 419, 484, 548, 640, 768, 904, 1033, 1189, 1409, 1673, 1938, 2223, 2599, 3083, 3612, 4162, 4823, 5683, 6696, 7775, 8986
OFFSET
0,5
COMMENTS
Low limiting ratio in 100th iteration near 1.16663.
The polynomial is interesting for the puzzling low ratio and the Salem like root structure with two complex roots outside the unit circle.
FORMULA
a(n) = a(n-1) + a(n-4) + a(n-6). - Franck Maminirina Ramaharo, Oct 31 2018
MATHEMATICA
CoefficientList[Series[1/(1 - x - x^4 + x^6), {x, 0, 60}], x]
PROG
(PARI) x='x+O('x^50); Vec(1/(1 - x - x^4 + x^6)) \\ G. C. Greubel, Nov 03 2018
(Magma) m:=50; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/(1 - x - x^4 + x^6))); // G. C. Greubel, Nov 03 2018
KEYWORD
nonn,easy
AUTHOR
Roger L. Bagula, Nov 28 2010
STATUS
approved