The number of idempotents in the partition monoid on [1..n].
A225797
The number of idempotents in the partition monoid on [1..n].
Terms
- a(0) =2a(1) =12a(2) =114a(3) =1512a(4) =25826a(5) =541254a(6) =13479500a(7) =389855014a(8) =12870896154a(9) =478623817564
External references
- oeis: A225797