Comment by AnotherGoodName
Comment by AnotherGoodName 8 days ago
Those are just columns that happen to share factors with 546 and happen to line up together. 546 is a very composite number (lots of factors!)
546n + 242 is always even
546n + 243 is always divisible by 3
546n + 244 is always even
546n + 255 is always divisible by 7.
Etc.
It's similar to how in base 10 you never see a prime ending in 0,2,4,6,8 or 5 since those numbers are clearly divisible by 2 or 5. In 546's case you have a lot of factors so even more gaps.
You also get the pattern appearing again since the number is even and the non-even factors repeat their pattern starting from the halfway point.
That makes perfect sense. Thank you.
To finish it off (skipping even numbers)...
546n + 247 is always divisible by 13.
546n + 249 is always divisible by 3.