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.

A072133 T_9(n) in the notation of Bergeron et al., u_k(n) in the notation of Gessel: Related to Young tableaux of bounded height.

Original entry on oeis.org

1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 3628799, 39916699, 478995537, 6226736369, 87166698628, 1307240982000, 20907446718225, 355162464899601, 6384776070987990, 121061600999380138, 2413632612087046844, 50453964720806671644, 1102844526263334763556
Offset: 0

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Author

Jesse Carlsson (j.carlsson(AT)physics.unimelb.edu.au), Jun 25 2002

Keywords

Crossrefs

Cf. A052399 for T_6(n), A047890 for T_5(n), A047889 for T_4(n).
Column k=9 of A214015.

Programs

  • Maple
    a:= proc(n) option remember;
          `if`(n<5, n!, ((-1110790863+(1520978576+(1772290401+(607308786+
           (101671498+(9464664+(500874+(14124+165*n)*n)*n)*n)*n)*n)*n)*n)*a(n-1)
           -(1129886062*n+559908333*n^2+111239576*n^3+10655238*n^4+8778*n^6
           +491700*n^5 +353895381)*(n-1)^2*a(n-2) +(258011271+234066216*n
           +58221266*n^2+5463876*n^3 +172810*n^4)*(n-1)^2*(n-2)^2*a(n-3)
           -9*(4070430+1504292*n+117469*n^2)* (n-1)^2*(n-2)^2*(n-3)^2*a(n-4)
           +893025*(n-1)^2*(n-2)^2*(n-3)^2*(n-4)^2*a(n-5)) /
           ((n+20)^2*(n+8)^2*(n+18)^2*(n+14)^2))
        end:
    seq(a(n), n=0..30);  # Alois P. Heinz, Oct 10 2012
  • Mathematica
    h[l_] := With[{n = Length[l]}, Sum[i, {i, l}]!/Product[Product[1 + l[[i]] - j + Sum[If[l[[k]] >= j, 1, 0], {k, i+1, n}], {j, 1, l[[i]]}], {i, 1, n}]]; g[n_, i_, l_] := If[n==0 || i==1, h[Join[l, Array[1 &, n]]]^2, If[i < 1, 0, Sum[g[n - i*j, i - 1, Join[l, Array[i &, j]]], {j, 0, n/i}]]]; a[n_] := If[n <= 9, n!, g[n, 9, {}]]; Table[a[n], {n, 1, 30}] (* Jean-François Alcover, Feb 24 2016, after Alois P. Heinz (A214015) *)

Formula

a(n) ~ 30625 * 3^(4*n + 90) / (2097152 * n^40 * Pi^4). - Vaclav Kotesovec, Sep 10 2014

Extensions

a(0)=1 prepended by Alois P. Heinz, Feb 09 2017