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.

A349022 G.f. satisfies A(x) = 1/(1 - x/(1 - x*A(x))^3)^4.

Original entry on oeis.org

1, 4, 22, 152, 1161, 9460, 80550, 708172, 6379368, 58576168, 546215580, 5158542152, 49239812893, 474285453628, 4604149947276, 44999181550032, 442430807369519, 4372944634271688, 43425156714959956, 433049078716727332, 4334925824762251939
Offset: 0

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Author

Seiichi Manyama, Nov 06 2021

Keywords

Crossrefs

Programs

  • Maple
    A349022 := proc(n)
        add(binomial(4*n-3*(k-1),k)*binomial(n+2*k-1,n-k)/(n-k+1),k=0..n) ;
    end proc:
    seq(A349022(n),n=0..40) ; # R. J. Mathar, Jan 25 2023
  • PARI
    a(n, s=3, t=4) = sum(k=0, n, binomial(t*n-(t-1)*(k-1), k)*binomial(n+(s-1)*k-1, n-k)/(n-k+1));

Formula

If g.f. satisfies: A(x) = 1/(1 - x/(1 - x*A(x))^s)^t, then a(n) = Sum_{k=0..n} binomial(t*n-(t-1)*(k-1),k) * binomial(n+(s-1)*k-1,n-k)/(n-k+1).