(MAGMAMagma) [Numerator((&+[(-1)^k*Factorial(n)*(9/11)^(n-2*k)/( Factorial(k) *Factorial(n-2*k)): k in [0..Floor(n/2)]])): n in [0..30]]; // G. C. Greubel, Jul 11 2018
(MAGMAMagma) [Numerator((&+[(-1)^k*Factorial(n)*(9/11)^(n-2*k)/( Factorial(k) *Factorial(n-2*k)): k in [0..Floor(n/2)]])): n in [0..30]]; // G. C. Greubel, Jul 11 2018
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From G. C. Greubel, Jul 11 2018: (Start)
a(n) = 11^n * Hermite(n, 9/22).
E.g.f.: exp(9*x - 121*x^2).
a(n) = numerator(Sum_{k=0..floor(n/2)} (-1)^k*n!*(9/11)^(n-2*k)/(k!*(n-2*k)!)). (End)
Table[11^n*HermiteH[n, 9/22], {n, 0, 30}] (* G. C. Greubel, Jul 11 2018 *)
(MAGMA) [Numerator((&+[(-1)^k*Factorial(n)*(9/11)^(n-2*k)/( Factorial(k) *Factorial(n-2*k)): k in [0..Floor(n/2)]])): n in [0..30]]; // G. C. Greubel, Jul 11 2018
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Numerators of 1, 9/11, -161/121, -5805/1331, 64641/14641, ...
Cf. A001020 (denominators).
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G. C. Greubel, <a href="/A159831/b159831.txt">Table of n, a(n) for n = 0..435</a>
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