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A281441
Triangle read by rows: T(n,r), 0 <= r <= n, is the number of idempotents of rank r in the Jones monoid J_n.
2
1, 0, 1, 1, 0, 1, 0, 4, 0, 1, 4, 0, 7, 0, 1, 0, 25, 0, 10, 0, 1, 25, 0, 57, 0, 13, 0, 1, 0, 196, 0, 98, 0, 16, 0, 1, 196, 0, 522, 0, 148, 0, 19, 0, 1, 0, 1764, 0, 1006, 0, 207, 0, 22, 0, 1, 1764, 0, 5206, 0, 1673, 0, 275, 0, 25, 0, 1
OFFSET
0,8
COMMENTS
Values were computed using the Semigroups package for GAP.
LINKS
Igor Dolinka, James East, Athanasios Evangelou, Desmond FitzGerald, Nicholas Ham, James Hyde, Nicholas Loughlin, Idempotent Statistics of the Motzkin and Jones Monoids, arXiv:1507.04838 [math.CO], 2015-2016.
FORMULA
T(2n,0) = T(2n+1,1) = A001246(n). T(2n+2,2n) = A016777(n). - Andrey Zabolotskiy, Oct 19 2017
CROSSREFS
Cf. A225798 (row sums), A281442, A289620, A001246, A016777.
Sequence in context: A115715 A292143 A350824 * A213600 A178104 A172545
KEYWORD
nonn,tabl
AUTHOR
James East, Oct 05 2017
STATUS
approved