login
A159660
Numerator of Hermite(n, 9/20).
1
1, 9, -119, -4671, 29361, 4001049, 6648441, -4741422831, -51980622879, 7118450923689, 157631179495401, -12818221231919391, -462152585977156719, 26604357682812127929, 1441035942685916620761, -61522878027700708614351, -4876813730307056239812159
OFFSET
0,2
LINKS
DLMF Digital library of mathematical functions, Table 18.9.1 for H_n(x)
FORMULA
D-finite with recurrence a(n) -9*a(n-1) +200*(n-1)*a(n-2)=0. [DLMF] - R. J. Mathar, Feb 16 2014
From G. C. Greubel, Jul 11 2018: (Start)
a(n) = 10^n * Hermite(n, 9/20).
E.g.f.: exp(9*x - 100*x^2).
a(n) = numerator(Sum_{k=0..floor(n/2)} (-1)^k*n!*(9/10)^(n-2*k)/(k!*(n-2*k)!)). (End)
EXAMPLE
Numerator of 1, 9/10, -119/100, -4671/1000, 29361/10000, 4001049/100000,...
MAPLE
A159660 := proc(n)
orthopoly[H](n, 9/20) ;
numer(%) ;
end proc: # R. J. Mathar, Feb 16 2014
MATHEMATICA
Numerator[Table[HermiteH[n, 9/20], {n, 0, 30}]] (* Vladimir Joseph Stephan Orlovsky, Jun 16 2011 *)
Table[10^n*HermiteH[n, 9/20], {n, 0, 50}] (* G. C. Greubel, Jul 11 2018 *)
PROG
(PARI) a(n)=numerator(polhermite(n, 9/20)) \\ Charles R Greathouse IV, Jan 29 2016
(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
CROSSREFS
Cf. A011557 (denominators)
Sequence in context: A210046 A130652 A054051 * A061172 A167593 A214698
KEYWORD
sign,frac
AUTHOR
N. J. A. Sloane, Nov 12 2009
STATUS
approved