A prime circle of order is a Circular Permutation of the numbers from 1 to with adjacent Pairs summing to a Prime. The number of prime circles for , 2, ..., are 1, 1, 1, 2, 48, ....

**References**

Filz, A. ``Problem 1046.'' *J. Recr. Math.* **14**, 64, 1982.

Filz, A. ``Problem 1046.'' *J. Recr. Math.* **15**, 71, 1983.

Guy, R. K. *Unsolved Problems in Number Theory, 2nd ed.* New York: Springer-Verlag, pp. 105-106, 1994.

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1999-05-26