OFFSET
0,2
COMMENTS
Hankel transform is (-7)^n.
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
FORMULA
a(n) = Sum_{k=0..n} A039599(n,k)*(-8)^k.
G.f.: 2/(9 - 7*sqrt(1-4*x)). - G. C. Greubel, May 31 2019
D-finite with recurrence 8*n*a(n) +(17*n+48)*a(n-1) +98*(-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+7*x*c), x=0, 25): seq(coeff(ser, x, n), n=0..22); - Emeric Deutsch, Mar 27 2007
MATHEMATICA
CoefficientList[Series[2/(9-7*Sqrt[1-4*x]), {x, 0, 30}], x] (* G. C. Greubel, May 31 2019 *)
PROG
(PARI) my(x='x+O('x^30)); Vec(2/(9-7*sqrt(1-4*x))) \\ G. C. Greubel, May 31 2019
(Magma) R<x>:=PowerSeriesRing(Rationals(), 30); Coefficients(R!( 2/(9 - 7*Sqrt(1-4*x)) )); // G. C. Greubel, May 31 2019
(Sage) (2/(9-7*sqrt(1-4*x))).series(x, 30).coefficients(x, sparse=False) # G. C. Greubel, May 31 2019
CROSSREFS
KEYWORD
sign
AUTHOR
Philippe Deléham, Mar 21 2007
EXTENSIONS
More terms from Emeric Deutsch, Mar 27 2007
STATUS
approved