Number of different hierarchical orderings that can be formed from n labeled elements: these are divided into groups and the elements in each group are then arranged in a "preferential arrangement" or "weak order" as in A000670.
A075729
Number of different hierarchical orderings that can be formed from n labeled elements: these are divided into groups and the elements in each group are then arranged in a "preferential arrangement" or "weak order" as in A000670.
Terms
- a(0) =1a(1) =1a(2) =4a(3) =23a(4) =173a(5) =1602a(6) =17575a(7) =222497a(8) =3188806a(9) =50988405a(10) =899222457a(11) =17329515172a(12) =362164300173
External references
- oeis: A075729