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.

A165257 Triangle in which n-th row is binomial(n+k-1,k), for column k=1..n.

Original entry on oeis.org

1, 2, 3, 3, 6, 10, 4, 10, 20, 35, 5, 15, 35, 70, 126, 6, 21, 56, 126, 252, 462, 7, 28, 84, 210, 462, 924, 1716, 8, 36, 120, 330, 792, 1716, 3432, 6435, 9, 45, 165, 495, 1287, 3003, 6435, 12870, 24310
Offset: 1

Views

Author

Daniel McLaury (daniel.mclaury(AT)gmail.com), Sep 11 2009

Keywords

Comments

T(n,k) is the number of non-descending sequences with length k and last number is less or equal to n. T(n,k) is also the number of integer partitions (of any positive integer) with length k and largest part is less or equal to n. - Zlatko Damijanic, Dec 06 2024

Examples

			1;
2, 3;
3, 6, 10;
4, 10, 20, 35;
5, 15, 35, 70, 126;
6, 21, 56, 126, 252, 462;
7, 28, 84, 210, 462, 924, 1716;
		

Crossrefs

A059481 with the first column (k = 0) removed.
Cf. A030662 (row sums), A001700 (diagonal).

Programs

  • Mathematica
    Table[Binomial[n+k-1,k],{n,10},{k,n}]//Flatten (* Harvey P. Dale, Jul 31 2021 *)
  • PARI
    tabl(nn) = {for (n=1, nn, for (k=1, n, print1( binomial(n+k-1, k), ", ");); print(););} \\ Michel Marcus, Jun 12 2013