OFFSET
0,2
COMMENTS
Hankel transform is (-9)^n.
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
FORMULA
a(n) = Sum_{k=0..n} A039599(n,k)*(-10)^k.
G.f.: 2/(11 - 9*sqrt(1-4*x)). - G. C. Greubel, May 28 2019
MAPLE
c:=(1-sqrt(1-4*x))/2/x: ser:=series(1/(1+9*x*c), x=0, 24): seq(coeff(ser, x, n), n=0..21); # Emeric Deutsch, Mar 23 2007
MATHEMATICA
CoefficientList[Series[2/(11-9*Sqrt[1-4*x]), {x, 0, 30}], x] (* G. C. Greubel, May 28 2019 *)
PROG
(PARI) my(x='x+O('x^30)); Vec(2/(11-9*sqrt(1-4*x))) \\ G. C. Greubel, May 28 2019
(Magma) R<x>:=PowerSeriesRing(Rationals(), 30); Coefficients(R!( 2/(11-9*Sqrt(1-4*x)) )); // G. C. Greubel, May 28 2019
(Sage) (2/(11-9*sqrt(1-4*x))).series(x, 30).coefficients(x, sparse=False) # G. C. Greubel, May 28 2019
CROSSREFS
KEYWORD
sign
AUTHOR
Philippe Deléham, Mar 21 2007
EXTENSIONS
More terms from Emeric Deutsch, Mar 23 2007
STATUS
approved