The number of permutations of {1,2,...,n,1,2,...,n} with the property that b(1) >= b(2) >= ... >= b(n) (there are b(k) numbers between the two k's for k=1..n).
A322178
The number of permutations of {1,2,...,n,1,2,...,n} with the property that b(1) >= b(2) >= ... >= b(n) (there are b(k) numbers between the two k's for k=1..n).
Terms
- a(0) =1a(1) =1a(2) =5a(3) =33a(4) =329a(5) =3825a(6) =57293a(7) =977581a(8) =19619645a(9) =442155529a(10) =11183272973a(11) =312134648549
External references
- oeis: A322178