84665

Appears in sequences

• Number of (n+2)X3 0..1 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically or nw-to-se diagonally exactly three ways, and new values 0..1 introduced in row major order.at n=17A204374
• a(n) = n*(7*n^2 + 15*n + 8)/6.at n=41A245301