OFFSET
0,2
COMMENTS
Denominator is 11^n. - Robert Israel, May 21 2014
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..434 (terms 0..82 from Robert Israel)
FORMULA
a(n) = 4*a(n-1) - 242*(n-1)*a(n-2) for n >= 2.
E.g.f.: exp(-11*x^2 + 4*x). - Robert Israel, May 21 2014
From G. C. Greubel, Jun 27 2018: (Start)
a(n) = 11^n * Hermite(n, 2/11).
a(n) = numerator(Sum_{k=0..floor(n/2)} (-1)^k*n!*(4/11)^(n-2*k)/(k!*(n-2*k)!)). (End)
MAPLE
MATHEMATICA
Numerator[Table[HermiteH[n, 2/11], {n, 0, 50}]] (* Vladimir Joseph Stephan Orlovsky, Apr 12 2011 *)
PROG
(PARI) a(n)=numerator(polhermite(n, 2/11)) \\ Charles R Greathouse IV, Jan 29 2016
(Magma) [Numerator((&+[(-1)^k*Factorial(n)*(4/11)^(n-2*k)/( Factorial(k) *Factorial(n-2*k)): k in [0..Floor(n/2)]])): n in [0..30]]; // G. C. Greubel, Jun 27 2018
CROSSREFS
KEYWORD
sign,frac
AUTHOR
N. J. A. Sloane, Nov 12 2009
STATUS
approved