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.

A162482 Expansion of (1/(1-x)^3)*M(x/(1-x)^3), M(x) the g.f. of Motzkin numbers A001006.

Original entry on oeis.org

1, 4, 14, 53, 218, 945, 4235, 19441, 90947, 432030, 2078416, 10105435, 49578341, 245131321, 1220218293, 6110131376, 30756858405, 155547919269, 789965192900, 4027121386190, 20600180351659, 105707046807196, 543973305719611
Offset: 0

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Author

Paul Barry, Jul 04 2009

Keywords

Crossrefs

Programs

  • Maple
    A162482 := proc(n)
        add(binomial(n+2*k+2,n-k)*A001006(k),k=0..n) ;
    end proc:
    seq(A162482(n),n=0..40) ; # R. J. Mathar, Feb 10 2015
  • Mathematica
    m[n_] := m[n] = If[n == 0, 1, m[n-1] + Sum[m[k]*m[n-2-k], {k, 0, n-2}]];
    a[n_] := Sum[Binomial[n+2k+2, n-k]*m[k], {k, 0, n}];
    Table[a[n], {n, 0, 22}] (* Jean-François Alcover, Apr 04 2024 *)

Formula

G.f.: 1/((1-x)^3-x-x^2/((1-x)^3-x-x^2/((1-x)^3-x-x^2/((1-x)^3-x-x^2/(1-... (continued fraction);
a(n) = Sum{k=0..n} C(n+2k+2,n-k)*A001006(k).
Conjecture: (n+2)*a(n) +4*(-2*n-1)*a(n-1) +18*(n-1)*a(n-2) +13*(-2*n+5)*a(n-3) +17*(n-4)*a(n-4) +3*(-2*n+11)*a(n-5) +(n-7)*a(n-6)=0. - R. J. Mathar, Feb 10 2015