Number of n X n 0..2 arrays with horizontal differences mod 3 never 1, vertical differences mod 3 never -1, and rows and columns lexicographically nondecreasing.

A229438

Number of n X n 0..2 arrays with horizontal differences mod 3 never 1, vertical differences mod 3 never -1, and rows and columns lexicographically nondecreasing.

Terms

    a(0) =3a(1) =7a(2) =22a(3) =109a(4) =753a(5) =6374a(6) =62205a(7) =676983a(8) =8026548a(9) =101907085a(10) =1368004992a(11) =19233435438a(12) =281169127711

External references