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Fifth column sequence of coefficient triangle A062137 of generalized Laguerre polynomials n!*L(n,3,x).
2

%I #24 Aug 09 2022 02:29:21

%S 1,40,1080,25200,554400,11975040,259459200,5708102400,128432304000,

%T 2968213248000,70643475302400,1733976211968000,43927397369856000,

%U 1148870392750080000,31019500604252160000,864410083505160192000

%N Fifth column sequence of coefficient triangle A062137 of generalized Laguerre polynomials n!*L(n,3,x).

%C The coefficients of the numerator polynomials N(m,x) of the e.g.f. for column m (here m=4) give triangle A062145.

%H Indranil Ghosh, <a href="/A062143/b062143.txt">Table of n, a(n) for n = 0..400</a>

%H <a href="/index/La#Laguerre">Index entries for sequences related to Laguerre polynomials</a>

%F a(n) = (n+4)!*binomial(n+7, 7)/4!;

%F E.g.f.: (1 + 28*x + 126*x^2 + 140*x^3 + 35*x^4)/(1-x)^12.

%F If we define f(n,i,x) = Sum_{k=i..n} Sum_{j=i..k} binomial(k,j) * Stirling1(n,k) * Stirling2(j,i) * x^(k-j) then a(n-4) = (-1)^n*f(n,4,-8), (n>=4). - _Milan Janjic_, Mar 01 2009

%e a(3) = (3+4)! * binomial(3+7,7) / 4! = (5040 * 120) / 24 = 25200. - _Indranil Ghosh_, Feb 23 2017

%t Table[(n+4)!*Binomial[n+7,7]/4!,{n,0,15}] (* _Indranil Ghosh_, Feb 23 2017 *)

%o (PARI) a(n) = (n+4)!*binomial(n+7,7)/4! \\ _Indranil Ghosh_, Feb 23 2017

%o (Python)

%o import math

%o f=math.factorial

%o def C(n,r):return f(n)/f(r)/f(n-r)

%o def A062143(n):return f(n+4)*C(n+7,7)/f(4) # _Indranil Ghosh_, Feb 23 2017

%o (Magma) [Factorial(n+4)*Binomial(n+7,7)/Factorial(4): n in [0..20]]; // _G. C. Greubel_, May 12 2018

%Y Cf. A062137, A062142, A062145.

%K nonn,easy

%O 0,2

%A _Wolfdieter Lang_, Jun 19 2001