a(n) is the number of symmetric permutations (p(1),p(2),...,p(m)) of (1,2,...,m), m=2n or m=2n+1, with p(m+1-k) = m+1-p(k) for 1<=k<=m, such that adjacent numbers do not differ by 1. a(n) is also the number of point-symmetric arrangements of m non-attacking kings on an m X m board, with one in each row and column.
A283184
a(n) is the number of symmetric permutations (p(1),p(2),...,p(m)) of (1,2,...,m), m=2n or m=2n+1, with p(m+1-k) = m+1-p(k) for 1<=k<=m, such that adjacent numbers do not differ by 1. a(n) is also the number of point-symmetric arrangements of m non-attacking kings on an m X m board, with one in each row and column.
Terms
- a(0) =1a(1) =0a(2) =2a(3) =14a(4) =122a(5) =1262a(6) =15466a(7) =219646a(8) =3551194a(9) =64431374a(10) =1296712778a(11) =28672204574a(12) =691007296954
External references
- oeis: A283184