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.

A334781 Array read by antidiagonals: T(n,k) = Sum_{i=1..n} binomial(1+i,2)^k.

Original entry on oeis.org

0, 0, 1, 0, 1, 2, 0, 1, 4, 3, 0, 1, 10, 10, 4, 0, 1, 28, 46, 20, 5, 0, 1, 82, 244, 146, 35, 6, 0, 1, 244, 1378, 1244, 371, 56, 7, 0, 1, 730, 8020, 11378, 4619, 812, 84, 8, 0, 1, 2188, 47386, 108020, 62003, 13880, 1596, 120, 9, 0, 1, 6562, 282124, 1047386, 867395, 256484, 35832, 2892, 165, 10
Offset: 0

Views

Author

Andrew Howroyd, May 15 2020

Keywords

Examples

			Array begins:
===============================================================
n\k | 0  1    2     3      4        5         6           7
----|----------------------------------------------------------
  0 | 0  0    0     0      0        0         0           0 ...
  1 | 1  1    1     1      1        1         1           1 ...
  2 | 2  4   10    28     82      244       730        2188 ...
  3 | 3 10   46   244   1378     8020     47386      282124 ...
  4 | 4 20  146  1244  11378   108020   1047386    10282124 ...
  5 | 5 35  371  4619  62003   867395  12438011   181141499 ...
  6 | 6 56  812 13880 256484  4951496  98204132  1982230040 ...
  7 | 7 84 1596 35832 871140 22161864 580094436 15475158552 ...
  ...
		

Crossrefs

Rows n=0..3 are A000004, A000012, A034472, A074508.
Main diagonal is A249564(n > 0).
Cf. A154283 (coefficients).

Programs

  • PARI
    T(n,k) = {sum(i=1, n, binomial(1+i,2)^k)}

Formula

T(n,k) = Sum_{i=0..2*(k-1)} A154283(k,i) * binomial(n+2+i, 2*k+i) for k > 0.