Number of n X 4 arrays with each row a permutation of 1..4 having at least as many downsteps as the preceding row.

A221619

Number of n X 4 arrays with each row a permutation of 1..4 having at least as many downsteps as the preceding row.

Terms

    a(0) =24a(1) =410a(2) =6120a(3) =85035a(4) =1130256a(5) =14576404a(6) =183919920a(7) =2282493365a(8) =27960543720a(9) =338950264686

External references