297729domain: NAppears in sequencesa(n) = a(n-1) + a(n-2) + a(n-3), with a(0) = 1, a(1) = a(2) = 8.at n=19A214830Number of nX5 0..1 arrays with every element equal to 1, 2, 4 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=8A300636