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A269736 Triangle read by rows: T(n,r) (0 <= r <= n) = number of idempotents of rank r in the Motzkin monoid M_n. 0
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 (list; table; graph; refs; listen; history; text; internal format)
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: A225476 A143777 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

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Last modified April 23 09:35 EDT 2019. Contains 322385 sequences. (Running on oeis4.)