Polyominoes determined by permutations
نویسندگان
چکیده
In the plane Z × Z a cell is a unit square, and a polyomino is a finite connected union of cells having no cut point. Polyominoes are defined up to translations. A column (row) of a polyomino is the intersection between the polyomino and an infinite strip of cells whose centers lie on a vertical (horizontal) line. The enumeration problem for general polyominoes is difficult to solve and still open. The number an of polyominoes with n cells is known up to n = 56 [JG] and asymptotically, this number satisfies the relation limn→∞ (an) 1/n = μ, 3.96 < μ < 4.64, where the lower bound is a recent improvement of [BMRR].
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