438866555650domain: NAppears in sequencesNumber of (n+2)X(1+2) 0..3 arrays with every consecutive three elements in every row and column having exactly 2 distinct values, in every diagonal 1 or 2 distinct values, in every antidiagonal 2 or 3 distinct values, and new values 0 upwards introduced in row major order.at n=13A252905