(MAGMAMagma) [Numerator((&+[(-1)^k*Factorial(n)*(14/27)^(n-2*k)/( Factorial(k) *Factorial(n-2*k)): k in [0..Floor(n/2)]])): n in [0..30]]; // G. C. Greubel, Sep 24 2018
(MAGMAMagma) [Numerator((&+[(-1)^k*Factorial(n)*(14/27)^(n-2*k)/( Factorial(k) *Factorial(n-2*k)): k in [0..Floor(n/2)]])): n in [0..30]]; // G. C. Greubel, Sep 24 2018
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Numerators of 1, 14/27, -1262/729, -58492/19683, 4701100/531441, ...
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G. C. Greubel, <a href="/A160107/b160107.txt">Table of n, a(n) for n = 0..376</a>
From G. C. Greubel, Sep 24 2018: (Start)
a(n) = 27^n * Hermite(n, 7/27).
E.g.f.: exp(14*x - 729*x^2).
a(n) = numerator(Sum_{k=0..floor(n/2)} (-1)^k*n!*(14/27)^(n-2*k)/(k!*(n-2*k)!)). (End)
Table[27^n*HermiteH[n, 7/27], {n, 0, 30}] (* G. C. Greubel, Sep 24 2018 *)
(PARI) x='x+O('x^30); Vec(serlaplace(exp(14*x - 729*x^2))) \\ G. C. Greubel, Sep 24 2018
(MAGMA) [Numerator((&+[(-1)^k*Factorial(n)*(14/27)^(n-2*k)/( Factorial(k) *Factorial(n-2*k)): k in [0..Floor(n/2)]])): n in [0..30]]; // G. C. Greubel, Sep 24 2018
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HermiteH[Range[0, 20], 7/27]//Numerator (* Harvey P. Dale, Jun 08 2018 *)
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