Number of preferential arrangements of n labeled elements such that the minimal number of elements per rank equals 2.
A245855
Number of preferential arrangements of n labeled elements such that the minimal number of elements per rank equals 2.
Terms
- a(0) =1a(1) =0a(2) =6a(3) =20a(4) =120a(5) =672a(6) =5516a(7) =40140a(8) =368640a(9) =3521870a(10) =37445298a(11) =422339502a(12) =5215454426a(13) =68144100780a(14) =954428684280
External references
- oeis: A245855