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A080896
Expansion of the exponential series exp( x * T(x) ) = exp( x / sqrt(1 - 2*x - 3*x^2) ), where T(x) is the ordinary generating series of the central trinomial coefficients (A002426).
1
1, 1, 3, 25, 265, 3741, 64051, 1298053, 30295665, 800411545, 23601417571, 768200763441, 27352316065273, 1057402991121205, 44102326806885075, 1973793512480683741, 94345589402816289121, 4796647490592139950513
OFFSET
0,3
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..379 (terms 0..100 from T. D. Noe)
FORMULA
E.g.f.: exp(x/sqrt(1 - 2*x - 3*x^2)).
MATHEMATICA
With[{nn=20}, CoefficientList[Series[Exp[x/Sqrt[1-2 x-3x^2]], {x, 0, nn}], x]Range[0, nn]!] (* Harvey P. Dale, Sep 08 2011 *)
PROG
(PARI) x='x + O('x^50); Vec(serlaplace(exp(x/sqrt(1 - 2*x - 3*x^2)))) \\ G. C. Greubel, Feb 27 2017
CROSSREFS
Cf. A002426.
Sequence in context: A357232 A355865 A009042 * A126746 A118989 A229162
KEYWORD
easy,nice,nonn
AUTHOR
Emanuele Munarini, Mar 31 2003
STATUS
approved