1051261domain: NAppears in sequencesNumber of squares (of another matrix) in M_2(n) - the ring of 2 X 2 matrices over Z_n.at n=40A068197Number of 4Xn 0..1 arrays with every element equal to 0, 1, 3, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=11A303042