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A159197
Numerator of Hermite(n, 2/9).
5
1, 4, -146, -1880, 63436, 1471984, -45495224, -1612749344, 45140586640, 2270685496384, -56732233335584, -3905439437484416, 85475082054073024, 7934074594685996800, -148274224427133801344, -18587578078456375947776, 285956053044109633474816
OFFSET
0,2
LINKS
FORMULA
From G. C. Greubel, Jun 10 2018: (Start)
a(n) = 9^n * Hermite(n,2/9).
E.g.f.: exp(4*x-81*x^2).
a(n) = numerator(Sum_{k=0..floor(n/2)} (-1)^k*n!*(4/9)^(n-2*k)/(k!*(n-2*k)!)). (End)
MATHEMATICA
Numerator[Table[HermiteH[n, 2/9], {n, 0, 50}]] (* Vladimir Joseph Stephan Orlovsky, Apr 01 2011*)
PROG
(PARI) a(n)=numerator(polhermite(n, 2/9)) \\ Charles R Greathouse IV, Jan 29 2016
(Magma) [Numerator((&+[(-1)^k*Factorial(n)*(4/9)^(n-2*k)/( Factorial(k) *Factorial(n-2*k)): k in [0..Floor(n/2)]])): n in [0..30]]; // G. C. Greubel, Jun 10 2018
CROSSREFS
Cf. A159030.
Sequence in context: A030450 A041629 A278845 * A246961 A331868 A180375
KEYWORD
sign,frac
AUTHOR
N. J. A. Sloane, Nov 12 2009
STATUS
approved