1286046720domain: NAppears in sequencesNumber of 4Xn 0..1 arrays with every element equal to 1, 2, 3, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=8A303104a(n) = n! * Sum_{k=1..n} k^2/floor(n/k).at n=9A342933