Number of idempotents in the partial Jones monoid.

Terms

a(0) =1a(1) =2a(2) =7a(3) =24a(4) =103a(5) =416a(6) =1998a(7) =8822a(8) =45661a(9) =213674a(10) =1167797a(11) =5694690a(12) =32445914a(13) =163151262a(14) =960580840a(15) =4945645808a(16) =29899013071a(17) =156834641076a(18) =968947169139