OFFSET
0,2
FORMULA
G.f.: A(x) = F(x)^2, where F(x) is the g.f. of A138020.
G.f.: (A(x)-1)/(A(x)+1) = 2*x*sqrt(A(x)) = 2*x*F(x).
G.f.: A(-x*A(x)) = 1/A(x).
G.f.: A(x) = 1 + 4*x*A(x)*B(x^2*A(x)), where B(x) is the g.f. of the central binomial coefficients A000984.
D-finite with recurrence (n-1)*(n+2)*(5*n-12)*a(n) +4*(-55*n^3+242*n^2-316*n+120)*a(n-2) -16*(n-3)*(n-4)*(5*n-2)*a(n-4)=0. - R. J. Mathar, Sep 27 2024
MAPLE
MATHEMATICA
CoefficientList[(InverseSeries[Series[x Sqrt[(1-2x)/(1+2x)], {x, 0, 25}]])^2/x^2, x]
CROSSREFS
KEYWORD
nonn
AUTHOR
Alexander Burstein, Feb 13 2024
STATUS
approved