login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A159857 Numerator of Hermite(n, 21/22). 1

%I #17 Sep 08 2022 08:45:44

%S 1,21,199,-5985,-270159,120141,329415351,6743277639,-416420774175,

%T -21799821766779,449168189050791,62188100645671791,110264394305901969,

%U -178278691994606939715,-4090744316373113328489,518102577833892931856151,25729556002946152951394241

%N Numerator of Hermite(n, 21/22).

%H Robert Israel, <a href="/A159857/b159857.txt">Table of n, a(n) for n = 0..435</a>

%F a(n) = 21*a(n-1) + 242*(1-n)*a(n-2). - _Robert Israel_, Dec 07 2017

%F From _G. C. Greubel_, Jun 02 2018: (Start)

%F a(n) = 11^n * Hermite(n, 21/22).

%F E.g.f.: exp(21*x - 121*x^2).

%F a(n) = numerator(Sum_{k=0..floor(n/2)} (-1)^k*n!*(21/11)^(n-2*k)/(k!*(n-2*k)!)). (End)

%e Numerators of 1, 21/11, 199/121, -5985/1331, -270159/14641

%p f:= gfun:-rectoproc({a(n) = 21*a(n-1)+242*(1-n)*a(n-2), a(0)=1, a(1)=21}, a(n), remember): map(f, [$0..40]); # _Robert Israel_, Dec 07 2017

%t Numerator[Table[HermiteH[n,21/22],{n,0,30}]] (* _Vladimir Joseph Stephan Orlovsky_, Jun 22 2011 *)

%t Table[11^n*HermiteH[n, 21/22], {n,0,30}] (* _G. C. Greubel_, Jul 11 2018 *)

%o (PARI) a(n)=numerator(polhermite(n, 21/22)) \\ _Charles R Greathouse IV_, Jan 29 2016

%o (Magma) [Numerator((&+[(-1)^k*Factorial(n)*(21/22)^(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. A001020 (denominators), A159850

%K sign,frac

%O 0,2

%A _N. J. A. Sloane_, Nov 12 2009

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 16 10:08 EDT 2024. Contains 371698 sequences. (Running on oeis4.)