OFFSET
0,2
COMMENTS
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
FORMULA
G.f.: (1 - sqrt(1-4*x))/(2*x*(1-4*x)^4).
D-finite with recurrence: n*(n+1)*a(n) -2*n*(4*n+13)*a(n-1) +8*(n+3)*(2*n+5)*a(n-2)=0. - R. J. Mathar, Jan 28 2020
MATHEMATICA
CoefficientList[Series[(1-Sqrt[1-4*x])/(2*x*(1-4*x)^4), {x, 0, 20}], x] (* G. C. Greubel, Feb 17 2019 *)
PROG
(PARI) my(x='x+O('x^20)); Vec((1-sqrt(1-4*x))/(2*x*(1-4*x)^4)) \\ G. C. Greubel, Feb 17 2019
(Magma) m:=20; R<x>:=PowerSeriesRing(Rationals(), m); Coefficients(R!( (1-Sqrt(1-4*x))/(2*x*(1-4*x)^4) )); // G. C. Greubel, Feb 17 2019
(Sage) ((1-sqrt(1-4*x))/(2*x*(1-4*x)^4)).series(x, 20).coefficients(x, sparse=False) # G. C. Greubel, Feb 17 2019
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
STATUS
approved