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A370289 G.f.: exp( Sum_{k>=1} (3*k)! / (3 * k!^3) * x^k/k ). 5
1, 2, 17, 218, 3404, 59644, 1127009, 22459358, 465607137, 9951077822, 217885806069, 4865577707714, 110439841557271, 2541477749853474, 59175695924948799, 1391881305657110326, 33029403365321798388, 789910458837089959548, 19021760426584464824327, 460890588704491541298970 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
FORMULA
G.f. A(x) = G(x)^(1/3), where G(x) is the g.f. for A229451.
G.f. A(x) = G(x)^2, where G(x) is the g.f. for A229452.
a(n) ~ c * 3^(3*n) / n^2, where c = 8 * 3^(1/2) * Pi * A370293^2 = 0.104583575...
MATHEMATICA
CoefficientList[Series[Exp[Sum[(3*k)!/(3*k!^3)*x^k/k, {k, 1, 20}]], {x, 0, 20}], x]
CoefficientList[Series[Exp[2*x*HypergeometricPFQ[{1, 1, 4/3, 5/3}, {2, 2, 2}, 27*x]], {x, 0, 20}], x]
CROSSREFS
Sequence in context: A333990 A349654 A364333 * A004029 A114268 A144208
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Feb 14 2024
STATUS
approved

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Last modified June 13 17:32 EDT 2024. Contains 373391 sequences. (Running on oeis4.)