Number of (n+3)X1 arrays of occupancy after each element moves up to +-n places but not 0.

A222557

Number of (n+3)X1 arrays of occupancy after each element moves up to +-n places but not 0.

Terms

    a(0) =4a(1) =64a(2) =359a(3) =1562a(4) =6220a(5) =24024a(6) =92011a(7) =352258a(8) =1351519

External references