perplexus.info :: Just Math : Chinese remainder to the rescue

Chinese remainder to the rescue (Posted on 2020-10-31)

A lattice point in the coordinate plane with origin O is called invisible if the segment OA contains a lattice point other than O and A. Let L be a positive integer. Show that there exists a square with side length L and sides parallel to the coordinate axes, such that all points in the square are invisible.

No Solution Yet Submitted by Danish Ahmed Khan

Rating: 3.0000 (1 votes)

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re: some progress

| Comment 2 of 3 |

(In reply to some progress by Steven Lord)

As per below -

"6) I have seen somewhere before this "comb" of lines (of multiples) used to search for primes (where new primes would lie off of any lines of multiples of known primes.) "

I was thinking of the Sieve of Eratosthenes

Edited on February 5, 2021, 9:51 pm

Posted by Steven Lord on 2021-02-05 21:47:09

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