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Physical Sciences and Mathematics Commons

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Mathematics

Journal of Humanistic Mathematics

Journal

2015

Enumerative combinatorics

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Full-Text Articles in Physical Sciences and Mathematics

Counting The Angels And Devils In Escher's Circle Limit Iv, John Choi, Nicholas Pippenger Jul 2015

Counting The Angels And Devils In Escher's Circle Limit Iv, John Choi, Nicholas Pippenger

Journal of Humanistic Mathematics

We derive the rational generating function that enumerates the angels and devils in M. C. Escher's Circle Limit IV according to their combinatorial distance from the six creatures whose feet meet at the center of the disk. This result shows that the base of the exponential rate of growth is 1.582... (the largest root of the polynomial 1 - z^2 - 2z^3 - z^4 + z^6).