Number of nX2 arrays containing 2 copies of 0..n-1 with no element 1 greater than its north, west or northeast neighbor modulo n and the upper left element equal to 0.

A266289

Number of nX2 arrays containing 2 copies of 0..n-1 with no element 1 greater than its north, west or northeast neighbor modulo n and the upper left element equal to 0.

Terms

    a(0) =1a(1) =0a(2) =2a(3) =9a(4) =435a(5) =20375a(6) =1624164a(7) =170338575a(8) =23301045360

External references