A269736 Triangle read by rows: T(n,r) (0 <= r <= n) = number of idempotents of rank r in the Motzkin monoid M_n.

1, 1, 1, 4, 2, 1, 16, 11, 3, 1, 81, 48, 19, 4, 1, 441, 266, 93, 28, 5, 1, 2601, 1492, 549, 152, 38, 6, 1, 16129, 9042, 3211, 947, 226, 49, 7, 1

Offset

0,4

Links

Table of n, a(n) for n=0..35.

I. Dolinka, J. East et al, Idempotent Statistics of the Motzkin and Jones Monoids, arXiv: 1507.04838 (2015), Table 2.

Example

Triangle begins:
1,
1,1,
4,2,1,
16,11,3,1,
81,48,19,4,1,
441,266,93,28,5,1,
2601,1492,549,152,38,6,1,
16129,9042,3211,947,226,49,7,1,
...

Crossrefs

First column is A001006(n)^2.

Row sums are A256672.

Sequence in context: A365566 A326659 A236830 * A264535 A256039 A152391

Adjacent sequences: A269733 A269734 A269735 * A269737 A269738 A269739

Keyword

nonn,tabl,more

Author

N. J. A. Sloane, Mar 13 2016

Status

approved