Counting the Number of Squares Reachable in k Knight’s Moves


Using geometric techniques, formulas for the number of squares that require k moves in order to be reached by a sole knight from its initial position on an infinite chessboard are derived. The number of squares reachable in exactly k moves are 1, 8, 32, 68, and 96 for k = 0, 1, 2, 3, and 4, respectively, and 28k – 20 for k ≥ 5. The cumulative number of squares reachable in k or fever moves are 1, 9, 41, and 109 for k = 0, 1, 2, and 3, respectively, and 14k2 6k + 5 for k ≥ 4. Although these formulas are known, the proofs that are presented are new and more mathematically accessible then preceding proofs.

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A. Miller and D. Farnsworth, "Counting the Number of Squares Reachable in k Knight’s Moves," Open Journal of Discrete Mathematics, Vol. 3 No. 3, 2013, pp. 151-154. doi: 10.4236/ojdm.2013.33027.

Conflicts of Interest

The authors declare no conflicts of interest.


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