OFFSET
3,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 3..1000
FORMULA
G.f.: x^3*C(x)^8/(1 - x/sqrt(1-4*x)). - G. C. Greubel, Jul 19 2019
a(n) ~ phi^(3*n-4) / sqrt(5), where phi = A001622 = (1+sqrt(5))/2 is the golden ratio. - Vaclav Kotesovec, Jul 19 2019
MATHEMATICA
Drop[CoefficientList[Series[(1-Sqrt[1-4x])^8/(2^8*x^5*(1-x/Sqrt[1-4x])), {x, 0, 40}], x], 3] (* G. C. Greubel, Jul 19 2019 *)
PROG
(PARI) my(x='x+O('x^40)); Vec((1-sqrt(1-4*x))^8/(2^8*x^5*(1-x/sqrt(1-4*x)))) \\ G. C. Greubel, Jul 19 2019
(Magma) R<x>:=PowerSeriesRing(Rationals(), 40); Coefficients(R!( (1-Sqrt(1-4*x))^8/(2^8*x^5*(1-x/Sqrt(1-4*x))) )); // G. C. Greubel, Jul 19 2019
(Sage) a=((1-sqrt(1-4*x))^8/(2^8*x^5*(1-x/sqrt(1-4*x)))).series(x, 45).coefficients(x, sparse=False); a[3:40] # G. C. Greubel, Jul 19 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved