302547337domain: NPropertiesPrimalityPrimeyesAppears in sequencesNumber of (n+2)X3 0..3 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically, diagonally or antidiagonally exactly three ways, and new values 0..3 introduced in row major order.at n=12A204635Prime numbersat n=16382881