27.--_The Dyer's Puzzle._

The correct answer is 18,816 different ways. The general formula for six

fleurs-de-lys for all squares greater than 2^{2} is simply this: Six

times the square of the number of combinations of _n_ things, taken three

at a time, where _n_ represents the number of fleurs-de-lys in the side

of the square. Of course where _n_ is even the remainders in rows and

columns will be even, and where _n_ is odd the remainders will be odd.

The Canterbury Puzzles, and Other Curious Problems · 第 180 / 286 题