Number of parenthesizings of products formed by n factors assuming nonassociativity and partial commutativity: individual factors commute, but bracketed expressions don't commute with anything.
A137591
Number of parenthesizings of products formed by n factors assuming nonassociativity and partial commutativity: individual factors commute, but bracketed expressions don't commute with anything.
Terms
- a(0) =1a(1) =1a(2) =6a(3) =54a(4) =660a(5) =10260a(6) =194040a(7) =4326840a(8) =111177360a(9) =3234848400a(10) =105135861600
External references
- oeis: A137591