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A062141
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Third column sequence of coefficient triangle A062137 of generalized Laguerre polynomials n!*L(n,3,x).
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4
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1, 18, 252, 3360, 45360, 635040, 9313920, 143700480, 2335132800, 39956716800, 719220902400, 13599813427200, 269729632972800, 5602076992512000, 121645100408832000, 2757288942600192000, 65140951268929536000, 1601701037083090944000, 40932359836567879680000
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OFFSET
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0,2
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LINKS
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FORMULA
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a(n) = (n+2)!*binomial(n+5, 5)/2!.
E.g.f.: (1 + 10*x + 10*x^2)/(1-x)^8.
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-5) = (-1)^(n-1)*f(n,5,-3), (n >= 5). - Milan Janjic, Mar 01 2009
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EXAMPLE
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a(2) = (2+2)! * binomial(2+5,5) / 2! = (24*21)/2 = 252. - Indranil Ghosh, Feb 24 2017
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MAPLE
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a:= n->(n+2)!*binomial(n+5, 5)/2!: seq(a(n), n=0..20); # Zerinvary Lajos, Apr 29 2007
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MATHEMATICA
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Table[(n+2)!*Binomial[n+5, 5]/2!, {n, 0, 15}] (* Indranil Ghosh, Feb 24 2017 *)
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PROG
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(Sage) [binomial(n, 5)*factorial (n-3)/2 for n in range(5, 21)] # Zerinvary Lajos, Jul 07 2009
(Python)
import math
f=math.factorial
def C(n, r):return f(n)/f(r)/f(n-r)
(PARI) x='x+O('x^30); Vec(serlaplace((1+10*x+10*x^2)/(1-x)^8)) \\ G. C. Greubel, May 11 2018
(Magma) [Factorial(n+2)*Binomial(n+5, 5)/2: n in [0..20]]; // G. C. Greubel, May 11 2018
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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