176372domain: NAppears in sequencesa(n) = 225*n^2 - n.at n=27A156813a(n) = 900*n^2 - 2*n.at n=13A158408a(n) = 784*n^2 - 28.at n=14A158657Number of (n+2)X(1+2) 0..3 arrays with every 3X3 subblock row and column sum not 2 4 5 or 7 and every diagonal and antidiagonal sum 2 4 5 or 7.at n=9A251869