190912

Appears in sequences

• Number of (n+2)X(n+2) 0..2 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically, diagonally or antidiagonally exactly three ways, and new values 0..2 introduced in row major order.at n=10A204276
• Number of domino tilings of the order n Aztec diamond which are diagonally symmetric.at n=7A374153