2700900

Appears in sequences

• a(n) = diagonal sum of left-justified array T given by A027052.at n=41A027069
• Number of 7 X (n+1) 0..1 arrays with every 2 X 2 subblock having the same number of equal edges as its horizontal neighbors and a different number from its vertical neighbors, and new values 0..1 introduced in row major order.at n=21A208088