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You are completely right; their pattern holds iff (I believe, not proven!) the number they take 75 for is even. If you take any even number of rows (== amount o
by tomsmeding 8y ago
You are completely right; their pattern holds iff (I believe, not proven!) the number they take 75 for is even. If you take any even number of rows (== amount of numbers per cell, in their construction), say 6, or 74, or 76, the pattern works.
- anderskaseorg 8y agoNo, it still fails for even n; see my other comment: https://news.ycombinator.com/item?id=17104624 https://news.ycombinator.com/item?id=17104624
- tomsmeding 8y agoFair point, I missed that. Scratch my claim. Then their claim that this pattern holds isn't even true; as pointed out elsewhere, and is obvious when you write out the sequence items explicitly in terms of their coordinates, any gcd!=1 cell will be red. But a gcd=1 cell need not be black, for many n.