OFFSET
0,2
COMMENTS
Hankel transform is (-4)^n.
For n>=37, all terms are negative. - Vaclav Kotesovec, May 30 2019
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
FORMULA
a(n) = Sum_{k=0..n} A039599(n,k)*(-5)^k.
G.f.: 1/(3 - 2*sqrt(1-4*x)). - G. C. Greubel, May 29 2019
a(n) ~ -4^n / (9*sqrt(Pi)*n^(3/2)). - Vaclav Kotesovec, May 30 2019
D-finite with recurrence -5*n*a(n) +2*(2*n-15)*a(n-1) +32*(2*n-3)*a(n-2)=0. - R. J. Mathar, Nov 22 2024
MAPLE
c:=(1-sqrt(1-4*x))/2/x: ser:=series(1/(1+4*x*c), x=0, 30): seq(coeff(ser, x, n), n=0..27); # Emeric Deutsch, Mar 23 2007
MATHEMATICA
CoefficientList[Series[1/(3-2*Sqrt[1-4*x]), {x, 0, 30}], x] (* G. C. Greubel, May 29 2019 *)
PROG
(PARI) my(x='x+O('x^30)); Vec(1/(3-2*sqrt(1-4*x))) \\ G. C. Greubel, May 29 2019
(Magma) R<x>:=PowerSeriesRing(Rationals(), 30); Coefficients(R!( 1/(3 - 2*Sqrt(1-4*x)) )); // G. C. Greubel, May 29 2019
(Sage) (1/(3-2*sqrt(1-4*x))).series(x, 30).coefficients(x, sparse=False) # G. C. Greubel, May 29 2019
CROSSREFS
KEYWORD
sign,changed
AUTHOR
Philippe Deléham, Mar 21 2007
EXTENSIONS
More terms from Emeric Deutsch, Mar 23 2007
STATUS
approved