Triangle read by rows: T(n,k) is the number of labeled commutative monoids of order n with k idempotents and a fixed identity.
A058160
Triangle read by rows: T(n,k) is the number of labeled commutative monoids of order n with k idempotents and a fixed identity.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =6a(5) =2a(6) =4a(7) =45a(8) =36a(9) =9a(10) =6a(11) =408a(12) =648a(13) =348a(14) =76a(15) =60a(16) =7195a(17) =13500a(18) =11790a(19) =5280a(20) =1065a(21) =120a(22) =200016a(23) =369930a(24) =425280a(25) =293640a(26) =118890a(27) =22566a(28) =1920a(29) =13811077
External references
- oeis: A058160