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.

A344563 T(n, k) = binomial(n - 1, k - 1) * binomial(n, k) * 2^k, T(0, 0) = 1. Triangle read by rows, T(n, k) for 0 <= k <= n.

Original entry on oeis.org

1, 0, 2, 0, 4, 4, 0, 6, 24, 8, 0, 8, 72, 96, 16, 0, 10, 160, 480, 320, 32, 0, 12, 300, 1600, 2400, 960, 64, 0, 14, 504, 4200, 11200, 10080, 2688, 128, 0, 16, 784, 9408, 39200, 62720, 37632, 7168, 256, 0, 18, 1152, 18816, 112896, 282240, 301056, 129024, 18432, 512
Offset: 0

Views

Author

Peter Luschny, May 30 2021

Keywords

Examples

			[0] 1;
[1] 0,  2;
[2] 0,  4,    4;
[3] 0,  6,   24,     8;
[4] 0,  8,   72,    96,     16;
[5] 0, 10,  160,   480,    320,     32;
[6] 0, 12,  300,  1600,   2400,    960,     64;
[7] 0, 14,  504,  4200,  11200,  10080,   2688,    128;
[8] 0, 16,  784,  9408,  39200,  62720,  37632,   7168,   256;
[9] 0, 18, 1152, 18816, 112896, 282240, 301056, 129024, 18432, 512.
		

Crossrefs

Row sums are A002003 with a(0) = 1, cf. also A047781.
The coefficients of the associated polynomials are in A103371.

Programs

  • Maple
    aRow := n -> seq(binomial(n-1, k-1)*binomial(n,k)*2^k, k=0..n):
    seq(print(aRow(n)), n=0..9);
  • Mathematica
    T[n_, k_] := Binomial[n-1, k-1] * Binomial[n, k] * 2^k;
    Table[T[n, k], {n, 0, 9}, {k, 0, n}] // Flatten
  • Python
    from math import comb
    def T(n, k):
        return comb(n-1, k-1)*comb(n, k)*2**k if k > 0 else k**n
    print([T(n, k) for n in range(10) for k in range(n+1)]) # Michael S. Branicky, May 30 2021