277150domain: NAppears in sequencesa(n) = a(n-1) + a(n-4), starting 1,1,1,3.at n=39A014101Number of n X 4 0..1 arrays with every element equal to 0, 1, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=18A302676