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.

A156739 Triangle T(n, k, m) = round( Product_{j=0..m} binomial(2*(n+j), 2*(k+j))/binomial( 2*(n-k+j), 2*j) ), where m = 6, read by rows.

Original entry on oeis.org

1, 1, 1, 1, 120, 1, 1, 3060, 3060, 1, 1, 38760, 988380, 38760, 1, 1, 319770, 103285710, 103285710, 319770, 1, 1, 1961256, 5226256926, 66199254396, 5226256926, 1961256, 1, 1, 9657700, 157843517260, 16494647553670, 16494647553670, 157843517260, 9657700, 1
Offset: 0

Views

Author

Roger L. Bagula, Feb 14 2009

Keywords

Examples

			Triangle begins as:
  1;
  1,       1;
  1,     120,          1;
  1,    3060,       3060,           1;
  1,   38760,     988380,       38760,          1;
  1,  319770,  103285710,   103285710,     319770,       1;
  1, 1961256, 5226256926, 66199254396, 5226256926, 1961256, 1;
		

Crossrefs

Cf. A086645 (m=0), this sequence (m=6), A156740 (m=7), A156741 (m=8), A156742 (m=9).

Programs

  • Magma
    A156739:= func< n,k | Round( (&*[Binomial(2*(n+j), 2*(k+j))/Binomial(2*(n-k+j), 2*j): j in [0..6]]) ) >;
    [A156739(n,k): k in [0..n], n in [0..12]]; // G. C. Greubel, Jun 18 2021
    
  • Mathematica
    b[n_, k_]:= Binomial[2*n, 2*k];
    T[n_, k_, m_]:= Round[Product[b[n+j, k+j]/b[n-k+j, j], {j,0,m}]];
    Table[T[n, k, 6], {n,0,12}, {k,0,n}]//Flatten (* G. C. Greubel, Jun 18 2021 *)
  • Sage
    def A156739(n, k): return round( product( binomial(2*(n+j), 2*(k+j))/binomial(2*(n-k+j), 2*j) for j in (0..6)) )
    flatten([[A156739(n,k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Jun 18 2021

Formula

T(n, k, m) = round( Product_{j=0..m} b(n+j, k+j)/b(n-k+j, j) ), where b(n, k) = binomial(2*n, 2*k) and m = 6.

Extensions

Definition corrected to give integral terms and edited by G. C. Greubel, Jun 18 2021