A256411 Triangle read by rows: T(n,k) (1 <= k <= n) = number of ascendingly generated semigroups of order n with k generators.
1, 2, 8, 3, 37, 113, 4, 145, 1257, 3492, 5, 452, 9020, 67394, 183732, 6, 1374, 60826, 938194, 6398792, 17061118, 7, 3933, 356023, 30492722, 466578957, 3032145644, 7743056064
Offset: 1
Examples
Triangle begins: 1; 2, 8; 3, 37, 113; 4, 145, 1257, 3492; 5, 452, 9020, 67394, 183732; 6, 1374, 60826, 938194, 6398792, 17061118; 7, 3933, 356023, 30492722, 466578957, 3032145644, 7743056064; ...
Links
- Alex Bailey, Martin Finn-Sell, Robert Snocken, Subsemigroup, ideal and congruence growth of free semigroups, arXiv preprint arXiv:1409.2444 [math.GR], 2014.