Have you ever seen this wonderful spiral ? The Ulam Spiral is arranging prime numbers in a clockwise spiral starting in 0.
Given an n by n matrix of 0s, fill it with 1 if the number is prime, in that order :
[7 8 9;
6 1 2;
5 4 3;]
Which will give you :
[1 0 0;
0 0 1;
1 0 1;]
As you experiment, look out for the strange patterns that emerge!
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Last Solution submitted on Jun 01, 2026

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Chris Cleveland Christian Schröder 玉印 Palla Sri Harsha Vardhan

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