OFFSET
0,11
COMMENTS
Limiting ratio is 1.2000265239873915.
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
Michael Mossinghoff, Small Salem Numbers
Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,1,-1).
FORMULA
G.f.: 1/((1 - x + x^2)*(1 - x^2 + x^4)*(1 - x^3 - x^4 + x^7 - x^10 - x^11 + x^14)).
a(n) = a(n-1) + a(n-10) + a(n-19) + a(n-20). - Franck Maminirina Ramaharo, Oct 31 2018
MAPLE
seq(coeff(series(1/(1 -x -x^10 -x^19 +x^20), x, n+1), x, n), n = 0..60); # G. C. Greubel, Dec 05 2019
MATHEMATICA
CoefficientList[Series[1/(1 -x -x^10 -x^19 +x^20), {x, 0, 60}], x]
PROG
(PARI) my(x='x+O('x^60)); Vec(1/(1 -x -x^10 -x^19 +x^20)) \\ G. C. Greubel, Nov 03 2018
(Magma) R<x>:=PowerSeriesRing(Integers(), 60); Coefficients(R!(1/(1 - x - x^10 - x^19 + x^20))); // G. C. Greubel, Nov 03 2018
(Sage)
def A175740_list(prec):
P.<x> = PowerSeriesRing(ZZ, prec)
return P( 1/(1 -x -x^10 -x^19 +x^20) ).list()
A175740_list(60) # G. C. Greubel, Dec 05 2019
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Roger L. Bagula, Dec 04 2010
STATUS
approved