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.

A142468 An eight-products triangle sequence of coefficients: T(n,k) = binomial(n,k) * Product_{j=1..7} j!*(n+j)!/((k+j)!*(n-k+j)!).

Original entry on oeis.org

1, 1, 1, 1, 9, 1, 1, 45, 45, 1, 1, 165, 825, 165, 1, 1, 495, 9075, 9075, 495, 1, 1, 1287, 70785, 259545, 70785, 1287, 1, 1, 3003, 429429, 4723719, 4723719, 429429, 3003, 1, 1, 6435, 2147145, 61408347, 184225041, 61408347, 2147145, 6435, 1
Offset: 0

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Author

Roger L. Bagula, Sep 20 2008

Keywords

Comments

Triangle of generalized binomial coefficients (n,k)A342889.%20-%20_N.%20J.%20A.%20Sloane">8; cf. A342889. - _N. J. A. Sloane, Apr 03 2021
Row sums are {1, 2, 11, 92, 1157, 19142, 403691, 10312304, 311348897, 10826298914, 426196716090, ...}.
The general function is T(n,m)L = binomial(n,m)*Product{k=1..L} k!*(n + k)!/((m + k)!*(n - m + k)!) to give the quadratic row {1, L+2, 1}.

Examples

			Triangle begins as:
  1;
  1,    1;
  1,    9,       1;
  1,   45,      45,        1;
  1,  165,     825,      165,         1;
  1,  495,    9075,     9075,       495,        1;
  1, 1287,   70785,   259545,     70785,     1287,       1;
  1, 3003,  429429,  4723719,   4723719,   429429,    3003,    1;
  1, 6435, 2147145, 61408347, 184225041, 61408347, 2147145, 6435, 1;
		

Crossrefs

Triangles of generalized binomial coefficients (n,k)_m (or generalized Pascal triangles) for m = 1,...,12: A007318 (Pascal), A001263, A056939, A056940, A056941, A142465, A142467, A142468, A174109, A342889, A342890, A342891.

Programs

  • Magma
    B:=Binomial; [B(n,k)*(&*[B(n+2*j, k+j)/B(n+2*j, j): j in [1..7]]): k in [0..n], n in [0..10]]; // G. C. Greubel, Nov 14 2019, Mar 03 2021
    
  • Maple
    b:= binomial;
    T:= (n, k) -> b(n, k)*mul(b(n+2*j, k+j)/b(n+2*j, j), j = 1..7);
    seq(seq(T(n, k), k = 0..n), n = 0..10); # G. C. Greubel, Nov 14 2019, Mar 03 2021
  • Mathematica
    T[n_, k_]:= T[n,k]= With[{B=Binomial}, B[n,k]* Product[B[n+2*j,k+j]/B[n+2*j,j], {j, 7}] ];
    Table[T[n, k], {n,0,10}, {k,0,n}]//Flatten (* modified by G. C. Greubel, Nov 14 2019, Mar 03 2021 *)
  • PARI
    T(n,k) = b=binomial; b(n,k)*prod(j=1,7, b(n+ 2*j,k+j)/b(n+2*j,j)); \\ G. C. Greubel, Nov 14 2019, Mar 03 2021
    
  • Sage
    b=binomial;
    def T(n, k): return b(n,k)*product(b(n+2*j,k+j)/b(n+2*j,j) for j in (1..7))
    [[T(n, k) for k in (0..n)] for n in (0..10)] # G. C. Greubel, Nov 14 2019, Mar 03 2021

Formula

T(n,k) = binomial(n,k)*Product_{j=1..7} j!*(n+j)!/((k+j)!*(n-k+j)!).

Extensions

Edited by G. C. Greubel, Nov 14 2019