An invisible figure is a polygon all of whose vertices (with possibly degenerate edges when restricted on a grid) are invisible from the
origin. There are invisible sets of every finite shape. The lower left-hand corner
of the invisible squares on a square grid with having smallest -coordinate and side lengths 1 and 2 are (20, 14) and (54,
20), respectively. The first invisible square has lower left-hand corner at (42273,
35397) (E. Weisstein, Mar. 1, 2009).
The first few
invisible squares occur at , , , , , ... (OEIS A157426
and A157427). The The first few invisible squares occur at , , , , , ... (OEIS A157428
and A157429). Both of these sets are plotted
above for the first 1000 such squares.
The filled square with lower left-hand corner at (1308, 1274) is the first square with which is completely invisible since its interior
point is invisible in addition to its edge midpoints and vertices.