491769283domain: NPropertiesPrimalityPrimeyesAppears in sequencesNumber of (n+2)X(2+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 1 2 5 6 or 7 and every 3X3 column and antidiagonal sum not equal to 1 2 5 6 or 7.at n=17A252568Prime numbersat n=25944744