A prime circle of order
is a free 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, 512, ... (OEIS A051252).
The prime circles for the first few even orders are given in the table below.
prime circles | |
2 | |
4 | |
6 | |
8 |