Number of permutations of 3 copies of 1..n with all adjacent differences <= 3 in absolute value.

A177293

Number of permutations of 3 copies of 1..n with all adjacent differences <= 3 in absolute value.

Terms

    a(0) =1a(1) =1a(2) =20a(3) =1680a(4) =369600a(5) =37850400a(6) =2626916040a(7) =171548183912

External references