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

%I #28 Aug 09 2022 02:29:26

%S 1,28,560,10080,176400,3104640,55883520,1037836800,19978358400,

%T 399567168000,8310997094400,179819755315200,4045944494592000,

%U 94612855873536000,2297740785500160000,57903067794604032000

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

%H Indranil Ghosh, <a href="/A062142/b062142.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+3)!*binomial(n+6, 6)/3!; e.g.f.: (1 + 18*x + 45*x^2 + 20*x^3)/(1-x)^10.

%F If we define f(n,i,x) = Sum_{k=1..n} Sum_{j=1..k} binomial(k,j)*Stirling1(n,k)*Stirling2(j,i)*x^(k-j), then a(n-3) = (-1)^(n-1)*f(n,3,-7), (n>=3). - _Milan Janjic_, Mar 01 2009

%e a(3) = (3+3)!*binomial(3+6,6)/3! = (720*84)/6 = 10080. - _Indranil Ghosh_, Feb 23 2017

%t Table[(n+3)!*Binomial[n+6,6]/3!,{n,0,15}] (* _Indranil Ghosh_, Feb 23 2017 *)

%o (Sage) [binomial(n,6)*factorial(n-3)/factorial(3) for n in range(6, 22)] # _Zerinvary Lajos_, Jul 07 2009

%o (PARI) a(n) =(n+3)!*binomial(n+6,6)/3! \\ _Indranil Ghosh_, Feb 23 2017

%o (Python)

%o import math

%o f=math.factorial

%o def C(n,r):

%o return f(n)/f(r)/f(n-r)

%o def A062142(n):return f(n+3)*C(n+6,6)/f(3) # _Indranil Ghosh_, Feb 23 2017

%o (Magma) [Factorial(n+3)*Binomial(n+6,6)/6: n in [0..20]]; // _G. C. Greubel_, May 12 2018

%Y Cf. A062137, A062141.

%K nonn,easy

%O 0,2

%A _Wolfdieter Lang_, Jun 19 2001