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.

Showing 1-3 of 3 results.

A141906 Triangle t(n,m) = (n*m)!/(m!^n) read by rows, 0<=m<=n.

Original entry on oeis.org

1, 1, 1, 1, 2, 6, 1, 6, 90, 1680, 1, 24, 2520, 369600, 63063000, 1, 120, 113400, 168168000, 305540235000, 623360743125120, 1, 720, 7484400, 137225088000, 3246670537110000, 88832646059788350720, 2670177736637149247308800
Offset: 0

Views

Author

Roger L. Bagula and Gary W. Adamson, Sep 14 2008

Keywords

Comments

Row sums are in A221177.

Examples

			1;
1, 1;
1, 2, 6;
1, 6, 90, 1680;
1, 24, 2520, 369600, 63063000;
1, 120, 113400, 168168000, 305540235000, 623360743125120;
1, 720, 7484400, 137225088000, 3246670537110000, 88832646059788350720, 2670177736637149247308800;
		

Crossrefs

Programs

  • Maple
    A141906 := proc(n,m)
            (n*m)!/m!^n ;
    end proc:
    seq(seq(A141906(n,m),m=0..n),n=0..5) ; # R. J. Mathar, Nov 08 2011
  • Mathematica
    Clear[t, n, m]; t[n_, m_] = (n*m)!/m!^n; Table[Table[t[n, m], {m, 0, n}], {n, 0, 10}]; Flatten[%]

A306241 a(n) = Sum_{k=0..n} (k*n)!/n!^k.

Original entry on oeis.org

1, 2, 8, 1702, 63097722, 623372476627154, 2670179107513625597282318, 7363615751879726008424500256018442794, 18165723935734974232438957032838329596079311234990642
Offset: 0

Views

Author

Seiichi Manyama, Jan 31 2019

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Sum[(k*n)!/n!^k,{k,0,n}],{n,0,10}] (* Vaclav Kotesovec, Feb 08 2019 *)
  • PARI
    {a(n) = sum(k=0, n, (k*n)!/n!^k)}

Formula

a(n) equals (row sums of A120666) + 1.
From Vaclav Kotesovec, Feb 08 2019: (Start)
a(n) ~ A034841(n).
a(n) ~ n^(n^2 - n/2 + 1) / (exp(1/12) * (2*Pi)^((n-1)/2)). (End)

A342107 a(n) = Sum_{k=0..n} (4*k)!/k!^4.

Original entry on oeis.org

1, 25, 2545, 372145, 63435145, 11796180169, 2320539673225, 474838887231625, 100035931337622625, 21552788197602942625, 4726913659271173170145, 1051798742538350304851425, 236861100204680963085573025
Offset: 0

Views

Author

Seiichi Manyama, Feb 28 2021

Keywords

Comments

Partial sums of A008977.
In general, for m > 1, Sum_{k=0..n} (m*k)!/k!^m ~ m^(m*n + m + 1/2) / ((m^m - 1) * (2*Pi*n)^((m-1)/2)). - Vaclav Kotesovec, Feb 28 2021

Crossrefs

Programs

  • Maple
    A342107 := proc(n)
        add((4*k)!/k!^4,k=0..n) ;
    end proc:
    seq(A342107(n),n=0..70) ; # R. J. Mathar, Dec 04 2023
  • Mathematica
    Table[Sum[(4*k)!/k!^4, {k, 0, n}], {n, 0, 20}] (* Vaclav Kotesovec, Feb 28 2021 *)
  • PARI
    a(n) = sum(k=0, n, (4*k)!/k!^4);

Formula

a(n) ~ 2^(8*n + 15/2) / (255 * Pi^(3/2) * n^(3/2)). - Vaclav Kotesovec, Feb 28 2021
D-finite with recurrence n^3*a(n) +(-257*n^3+384*n^2-176*n+24)*a(n-1) +8*(4*n-3)*(2*n-1)*(4*n-1)*a(n-2)=0. - R. J. Mathar, Dec 04 2023
Showing 1-3 of 3 results.