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.

A127742 Triangle read by rows with shape A000041 which refines the Catalan triangle A033184 using sequence A048996.

Original entry on oeis.org

1, 1, 1, 2, 2, 1, 5, 4, 1, 3, 1, 14, 10, 4, 6, 3, 4, 1, 42, 28, 10, 4, 15, 12, 1, 8, 6, 5, 1, 132, 84, 28, 20, 42, 30, 12, 6, 20, 24, 4, 10, 10, 6, 1, 429, 264, 84, 56, 25, 126, 84, 60, 15, 12, 56, 60, 24, 24, 1, 25, 40, 10, 12, 15, 7, 1, 1430, 858, 264, 168, 140, 396, 252, 168, 75
Offset: 1

Views

Author

Alford Arnold, Feb 23 2007

Keywords

Comments

Contribution from R. J. Mathar, Jul 16 2010: (Start)
The entries count Dyck paths of length 2n which have a step/stride pattern between consecutive returns to the horizontal axes (after sorting) equivalent to the k-th partition of n.
Equivalent means that each distance between two x (where y=0) is divided by 2 prior to comparison.
Example: if the x-values are (0,4,8,10,16) with 2n=16, the strides are 4,4,2,6, equal to 2,2,1,3 after division by 2, and contribute to the 1^1,2^2,3^1 partition T(8,14). (End)

Examples

			The triangle begins
1
1 1
2 2 1
5 4 1 3 1
14 10 4 6 3 4 1
etc
		

Extensions

More terms from R. J. Mathar, Jul 16 2010