p a b o c n d m q e l f k g j i h |
Arrange the numbers 1-17 at positions a-q in the octagon, such that the eight
sides (i.e. pab, bcd, ...) and the eight lines through the center (i.e. aqi, bqj,
...) all have the same sum.
For ease in comparing solutions, let 'a' be the smallest of (a,c,e,g,i,k,m,o) and 'b' be less than 'p'. |

Solutions were received from Dennis Molter, Denis Borris, Radu Ionescu, Claudio Baiocchi, Joseph DeVincentis, and Philippe Fondanaiche. The common sum is 27 and the center number must be 9. There are four possible solutions:

16 1 10 6 14 5 3 7 9 11 15 13 4 12 8 17 2 | 14 1 12 2 10 11 5 3 9 15 13 7 8 16 6 17 4 | 15 2 10 11 13 1 4 12 9 6 14 17 5 7 8 16 3 | 17 3 7 8 14 2 6 13 9 5 12 16 4 10 11 15 1 |

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