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A058142 Triangle read by rows: number of commutative monoids of order n with k idempotents. 6
1, 1, 1, 1, 3, 1, 2, 9, 6, 2, 1, 26, 30, 16, 5, 1, 98, 142, 111, 54, 15, 1, 455, 718, 713, 482, 215, 53, 3, 4018, 4277, 4637, 3919, 2414, 996, 222, 2, 101910, 36124, 32937, 31308, 24047, 13758, 5294, 1078, 1, 10054303, 708355, 290278, 260758, 229411, 164216, 88178, 31867, 5994 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
1,5
LINKS
EXAMPLE
Triangle begins:
1;
1, 1;
1, 3, 1;
2, 9, 6, 2;
1, 26, 30, 16, 5;
1, 98, 142, 111, 54, 15;
...
CROSSREFS
Row sums give A058131.
Main diagonal: A006966.
Columns 1..2: A000688, A058143.
Sequence in context: A238388 A074308 A237186 * A058144 A132323 A305097
KEYWORD
nonn,tabl,hard
AUTHOR
Christian G. Bower, Nov 14 2000
EXTENSIONS
a(30)-a(55) from Andrew Howroyd, Feb 15 2022
STATUS
approved

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Last modified March 29 03:51 EDT 2024. Contains 371264 sequences. (Running on oeis4.)