Sequence a(n) gives the number of ways to seat 2n people around a circular table so that person i does not sit across from person n+i for any 1 <= i <= n.
A167406
Sequence a(n) gives the number of ways to seat 2n people around a circular table so that person i does not sit across from person n+i for any 1 <= i <= n.
Terms
- a(0) =0a(1) =4a(2) =64a(3) =2880a(4) =208896a(5) =23193600a(6) =3640688640a(7) =768126320640
External references
- oeis: A167406