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%I #16 Sep 08 2022 08:45:44
%S 1,9,-119,-4671,29361,4001049,6648441,-4741422831,-51980622879,
%T 7118450923689,157631179495401,-12818221231919391,-462152585977156719,
%U 26604357682812127929,1441035942685916620761,-61522878027700708614351,-4876813730307056239812159
%N Numerator of Hermite(n, 9/20).
%H G. C. Greubel, <a href="/A159660/b159660.txt">Table of n, a(n) for n = 0..441</a>
%H DLMF <a href="https://dlmf.nist.gov/18.9">Digital library of mathematical functions</a>, Table 18.9.1 for H_n(x)
%F D-finite with recurrence a(n) -9*a(n-1) +200*(n-1)*a(n-2)=0. [DLMF] - _R. J. Mathar_, Feb 16 2014
%F From _G. C. Greubel_, Jul 11 2018: (Start)
%F a(n) = 10^n * Hermite(n, 9/20).
%F E.g.f.: exp(9*x - 100*x^2).
%F a(n) = numerator(Sum_{k=0..floor(n/2)} (-1)^k*n!*(9/10)^(n-2*k)/(k!*(n-2*k)!)). (End)
%e Numerator of 1, 9/10, -119/100, -4671/1000, 29361/10000, 4001049/100000,...
%p A159660 := proc(n)
%p orthopoly[H](n,9/20) ;
%p numer(%) ;
%p end proc: # _R. J. Mathar_, Feb 16 2014
%t Numerator[Table[HermiteH[n, 9/20], {n, 0, 30}]] (* _Vladimir Joseph Stephan Orlovsky_, Jun 16 2011 *)
%t Table[10^n*HermiteH[n, 9/20], {n,0,50}] (* _G. C. Greubel_, Jul 11 2018 *)
%o (PARI) a(n)=numerator(polhermite(n,9/20)) \\ _Charles R Greathouse IV_, Jan 29 2016
%o (Magma) [Numerator((&+[(-1)^k*Factorial(n)*(9/10)^(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
%Y Cf. A011557 (denominators)
%K sign,frac
%O 0,2
%A _N. J. A. Sloane_, Nov 12 2009
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