A062197 Row sums of signed triangle A062139 (generalized a=2 Laguerre).
1, 2, 5, 14, 37, 34, -887, -14050, -168919, -1916542, -21607859, -245387858, -2799384755, -31558843486, -337767590383, -3063846770626, -11912361112367, 477367592119810, 21032925955607701, 627398853149961038, 16703816669710968821
Offset: 0
Links
Crossrefs
Cf. A062139.
Programs
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Magma
[Factorial(n)*(&+[(-1)^k*Binomial(n+2, n-k)/Factorial(k): k in [0..n]]): n in [0..30]]; // G. C. Greubel, May 13 2018
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Maple
a := n -> (n+2)!*hypergeom([-n],[3],1)/2: seq(simplify(a(n)), n=0..20); # Peter Luschny, Apr 11 2015
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Mathematica
Table[n!*LaguerreL[n, 2, 1],{n,0,20}] (* Vaclav Kotesovec, Aug 01 2013 *)
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PARI
for(n=0,30, print1(n!*sum(k=0,n, (-1)^k*binomial(n+2, n-k)/k!), ", ")) \\ G. C. Greubel, May 13 2018
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PARI
a(n) = vecsum(Vec(n!*pollaguerre(n, 2))); \\ Michel Marcus, Feb 06 2021
Formula
E.g.f.: exp(-x/(1-x))/(1-x)^3.
a(n) = Sum_{m=0..n} ((-1)^m)*n!*binomial(n+2, n-m)/m!.
a(n) = 2*n*a(n-1) - (n-1)*(n+1)*a(n-2). - Vaclav Kotesovec, Aug 01 2013
a(n) = (n+2)!*hypergeom([-n],[3],1)/2. - Peter Luschny, Apr 11 2015