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A175773
Expansion of 1/(1 - x - x^6 - x^11 + x^12).
23
1, 1, 1, 1, 1, 1, 2, 3, 4, 5, 6, 8, 10, 13, 17, 22, 28, 37, 48, 62, 80, 103, 133, 172, 223, 289, 374, 483, 625, 808, 1045, 1352, 1749, 2262, 2926, 3785, 4896, 6333, 8191, 10595, 13704, 17726, 22929, 29659, 38363, 49622, 64185, 83022, 107388, 138905, 179672
OFFSET
0,7
COMMENTS
The ratio a(n+1)/a(n) is 1.2934859531254534... for n->infinity.
LINKS
Michael Mossinghoff, Small Salem numbers
FORMULA
G.f.: 1/((1 - x + x^2)*(1 - x^2 - x^3 + x^5 - x^7 - x^8 + x^10)).
a(n) = a(n-1) + a(n-6) + a(n-11) - a(n-12), n >= 12. - Franck Maminirina Ramaharo, Oct 31 2018
MATHEMATICA
CoefficientList[Series[1/(1 - x - x^6 - x^11 + x^12), {x, 0, 50}], x]
PROG
(PARI) x='x+O('x^50); Vec(1/(1-x-x^6-x^11+x^12)) \\ G. C. Greubel, Nov 03 2018
(Magma) m:=50; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/(1-x-x^6-x^11+x^12))); // G. C. Greubel, Nov 03 2018
KEYWORD
nonn,easy
AUTHOR
Roger L. Bagula, Dec 04 2010
STATUS
approved