Triangle read by rows: T(n,k) = number of partial idempotent mappings (of an n-chain) with collapse exactly k.
A259759
Triangle read by rows: T(n,k) = number of partial idempotent mappings (of an n-chain) with collapse exactly k.
Terms
- a(0) =1a(1) =2a(2) =0a(3) =4a(4) =0a(5) =2a(6) =8a(7) =0a(8) =12a(9) =3a(10) =16a(11) =0a(12) =48a(13) =24a(14) =16a(15) =32a(16) =0a(17) =160a(18) =120a(19) =160a(20) =65a(21) =64a(22) =0a(23) =480a(24) =480a(25) =960a(26) =780a(27) =336a(28) =128a(29) =0
External references
- oeis: A259759