Number of finite, negative, totally ordered monoids of size n (semigroups with a neutral element that is also the top element).
A253950
Number of finite, negative, totally ordered monoids of size n (semigroups with a neutral element that is also the top element).
Terms
- a(0) =1a(1) =1a(2) =2a(3) =8a(4) =44a(5) =308a(6) =2641a(7) =27120a(8) =332507a(9) =5035455
External references
- oeis: A253950