A058157
Triangle read by rows: T(n,k) is the number of labeled monoids of order n with k idempotents.
Original entry on oeis.org
1, 2, 2, 3, 18, 12, 16, 180, 288, 140, 30, 2640, 6540, 8380, 3020, 480, 119610, 238200, 421020, 372360, 100362, 840, 25196052, 13786290, 26803000, 36174600, 22822674, 4768624, 22080, 48687313640, 2254725312, 2358499080, 3849768160, 3859581096, 1826525120, 305498328
Offset: 1
Triangle begins:
1;
2, 2;
3, 18, 12;
16, 180, 288, 140;
30, 2640, 6540, 8380, 3020;
...
A058158
Triangle read by rows: T(n,k) is the number of labeled monoids of order n with k idempotents and a fixed identity.
Original entry on oeis.org
1, 1, 1, 1, 6, 4, 4, 45, 72, 35, 6, 528, 1308, 1676, 604, 80, 19935, 39700, 70170, 62060, 16727, 120, 3599436, 1969470, 3829000, 5167800, 3260382, 681232, 2760, 6085914205, 281840664, 294812385, 481221020, 482447637, 228315640, 38187291
Offset: 1
Triangle begins:
1;
1, 1;
1, 6, 4;
4, 45, 72, 35;
6, 528, 1308, 1676, 604;
80, 19935, 39700, 70170, 62060, 16727;
...
A351730
Number of labeled idempotent semigroups of order n.
Original entry on oeis.org
1, 1, 4, 35, 604, 16727, 681232, 38187291, 2810370122, 261999605819
Offset: 0
Showing 1-3 of 3 results.
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