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%I #9 Nov 17 2016 09:41:23
%S 1,4,768,1555200,20808990720,9029615616000000,1415988202438656000000,
%T 536259842454308939366400000,7188611938994779905746534400000000,
%U 503281313253202450261043834781696000000
%N Denominator of coefficient of (-x^2)^n in F(x)*F(-x) where F(x)=sum(k>=0,x^k/(k!)^3).
%D Bruce Berndt, Ramanujan's Notebooks Part II, Springer-Verlag; see Hypergeometric series, p. 62.
%F F(x)*F(-x)=sum(n>=0, (3n)!/(n!)^3/((2n)!)^3*(-x^2)^n)
%t F[x_] := HypergeometricPFQ[{}, {1, 1}, x]; F[x]*F[-x] + O[x]^20 // CoefficientList[#, x^2]& // Denominator (* _Jean-François Alcover_, Nov 17 2016 *)
%Y Cf. A068113.
%K easy,frac,nonn
%O 0,2
%A _Benoit Cloitre_, Mar 21 2002
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