Number of nX3 0..4 arrays with each element equal to the number its horizontal and vertical zero neighbors
2, 4, 10, 18, 38, 78, 156, 320, 654, 1326, 2706, 5518, 11228, 22884, 46634, 94978
2 seqfan posts
Mon Oct 10 14:04:36 CEST 2011 [seqfan] Self-integers tiling the plane