OFFSET
0,3
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (1,1,-1,0,0,0,0,0,0,1,-1,-1,1).
FORMULA
G.f.: (1+x^11)/((1-x^2)^2*(1-x^10)) (from MAPLE line).
a(n) = floor((11*(2*n+3)*(-1)^n+2*n^2+6*n+79)/80). - Tani Akinari, Jul 25 2013
G.f.: (1 -x +x^2 -x^3 +x^4 -x^5 +x^6 -x^7 +x^8 -x^9)/( (1-x+x^2-x^3+x^4)* (1+x+x^2+x^3+x^4)*(1+x)^2*(1-x)^3 ). - R. J. Mathar, Dec 18 2014
MAPLE
seq(coeff(series((1+x^11)/((1-x^2)^2*(1-x^10)), x, n+1), x, n), n = 0..80);
MATHEMATICA
LinearRecurrence[{1, 1, -1, 0, 0, 0, 0, 0, 0, 1, -1, -1, 1}, {1, 0, 2, 0, 3, 0, 4, 0, 5, 0, 7, 1, 9}, 80] (* Ray Chandler, Jul 15 2015 *)
PROG
(PARI) my(x='x+O('x^80)); Vec((1+x^11)/((1-x^2)^2*(1-x^10))) \\ G. C. Greubel, Sep 12 2019
(Magma) R<x>:=PowerSeriesRing(Integers(), 80); Coefficients(R!( (1+x^11)/((1-x^2)^2*(1-x^10)) )); // G. C. Greubel, Sep 12 2019
(Sage)
def A008803_list(prec):
P.<x> = PowerSeriesRing(ZZ, prec)
return P((1+x^11)/((1-x^2)^2*(1-x^10))).list()
A008803_list(80) # G. C. Greubel, Sep 12 2019
(GAP) a:=[1, 0, 2, 0, 3, 0, 4, 0, 5, 0, 7, 1, 9];; for n in [14..80] do a[n]:=a[n-1] +a[n-2]-a[n-3]+a[n-10]-a[n-11]-a[n-12]+a[n-13]; od; a; # G. C. Greubel, Sep 12 2019
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved