Triangle: T(n,k), k<=n: commutative groupoids with a nontrivial symmetry with n elements and k idempotents.
A038023
Triangle: T(n,k), k<=n: commutative groupoids with a nontrivial symmetry with n elements and k idempotents.
Terms
- a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =3a(7) =6a(8) =0a(9) =4a(10) =96a(11) =214a(12) =128a(13) =64a(14) =38a(15) =54248a(16) =83925a(17) =54223a(18) =28254a(19) =10223a(20) =1894
External references
- oeis: A038023