Number of multiset permutations of {1, 1, 2, 2, ..., n, n} with no fixed pair (j,j).

A374980

Number of multiset permutations of {1, 1, 2, 2, ..., n, n} with no fixed pair (j,j).

Terms

    a(0) =1a(1) =0a(2) =5a(3) =74a(4) =2193a(5) =101644a(6) =6840085a(7) =630985830a(8) =76484389121

External references