Triangle: T(n,k), k<=n: commutative groupoids with no symmetry with n elements and k idempotents.
A038022
Triangle: T(n,k), k<=n: commutative groupoids with no symmetry with n elements and k idempotents.
Terms
- a(0) =1a(1) =0a(2) =1a(3) =1a(4) =2a(5) =1a(6) =35a(7) =51a(8) =27a(9) =3a(10) =13776a(11) =18330a(12) =9152a(13) =2016a(14) =164a(15) =83306272a(16) =104124850a(17) =52056277a(18) =13006746a(19) =1622527a(20) =80461
External references
- oeis: A038022