Triangle read by rows: number of nilpotent partial transformations (of an n-element set) of height r (height(alpha) = |Im(alpha)|), 0 <= r < n.
A141618
Triangle read by rows: number of nilpotent partial transformations (of an n-element set) of height r (height(alpha) = |Im(alpha)|), 0 <= r < n.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =1a(4) =9a(5) =6a(6) =1a(7) =28a(8) =72a(9) =24a(10) =1a(11) =75a(12) =500a(13) =600a(14) =120a(15) =1a(16) =186a(17) =2700a(18) =7800a(19) =5400a(20) =720a(21) =1a(22) =441a(23) =12642a(24) =73500a(25) =117600a(26) =52920a(27) =5040a(28) =1a(29) =1016
External references
- oeis: A141618