cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A062147 Row sums of unsigned triangle A062137 (generalized a=3 Laguerre).

Original entry on oeis.org

1, 5, 31, 229, 1961, 19081, 207775, 2501801, 32989969, 472630861, 7307593151, 121247816845, 2148321709561, 40476722545169, 807927483311551, 17028146983530961, 377844723929464865, 8803698102396787861, 214877019857456672479, 5482159931449737760181
Offset: 0

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Author

Wolfdieter Lang, Jun 19 2001

Keywords

Crossrefs

Programs

  • Magma
    [Factorial(n)*(&+[Binomial(n+3,n-m)/Factorial(m): m in [0..n]]): n in [0..30]]; // G. C. Greubel, Feb 06 2018
    
  • Maple
    A062147 := n -> n!*simplify(LaguerreL(n,3,-1), 'LaguerreL');
    seq(A062147(n), n = 0 .. 30); # G. C. Greubel, Mar 10 2021
  • Mathematica
    Table[Sum[n!*Binomial[n+3,n-k]/k!,{k,0,n}],{n,0,20}]
    (* or *)
    Table[n!*SeriesCoefficient[E^(x/(1-x))/(1-x)^4,{x,0,n}],{n,0,20}] (* Vaclav Kotesovec, Oct 11 2012 *)
  • PARI
    my(x='x+O('x^66)); Vec(serlaplace(exp(x/(1-x))/(1-x)^4)) \\ Joerg Arndt, May 06 2013
    
  • PARI
    a(n) = vecsum(apply(abs,Vec(n!*pollaguerre(n, 3)))); \\ Michel Marcus, Feb 06 2021
    
  • Sage
    [factorial(n)*gen_laguerre(n, 3, -1) for n in (0..30)] # G. C. Greubel, Mar 10 2021

Formula

E.g.f.: exp(x/(1-x))/(1-x)^4.
a(n) = Sum_{m=0..n} n!*binomial(n+3, n-m)/m!.
a(n) = (2*n+3)*a(n-1) - (n-1)*(n+2)*a(n-2). - Vaclav Kotesovec, Oct 11 2012
a(n) ~ exp(2*sqrt(n)-n-1/2)*n^(n+7/4)/sqrt(2). - Vaclav Kotesovec, Oct 11 2012
a(n) = n!*LaguerreL(n, 3, -1). - G. C. Greubel, Mar 10 2021