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It will probably take you a very long time to work out the special property of this 4-coloured 17 x 17 square.

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Four Corners



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A mixture of intarsia and the log cabin method.

The knitting  starts in the centre and works outwards.


Use any yarn in four distinctly different colours. The original was made in DK yarn. Using a different yarn will change the overall size of the afghan.

The pattern includes instructions for changing the size in various different ways and for using crochet squares.

In 2012, an American mathematician named Bill Gasarch offered a prize of $289 to anyone who could find a way to colour an arrangement of 17 x 17 squares in such a way that no square or rectangle within it had four corners in the same colour. The prize was collected by Bernd Steinbach and Christian Posthoff. Click here to read the announcement. They also found a solution for an 18 x 18 square.

17 x 17 = 289, hence the prize that was offered.

In 2019 Sameer Shah presented this square as one of his favourite pieces of maths in a (not very serious) competition to find The World’s Most Interesting Mathematician (2019).

This was my inspiration for making the wall-hanging.