perplexus.info :: Numbers : Nonnegative Integer Crossed Prime Puzzle

Nonnegative Integer Crossed Prime Puzzle (Posted on 2024-01-05)

Determine the total number of nonnegative integer values of n such that ⌊n³/9⌋ is a prime number.

Notes:
1) ⌊x⌋ is the floor of n, which is equal to the greatest integer less than or equal to n.
2) Adapted from a problem appearing in Phillipines Mathematical Olympiad, 2020.

See The Solution Submitted by K Sengupta

Rating: 5.0000 (1 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)

computer exploration--no proof of completeness

| Comment 1 of 6

for n=0:100000

p=floor(n^3/9);

if isprime(p)

disp([n p])

end

find only 3, testing 0 through 100,000:

Posted by Charlie on 2024-01-05 08:55:30

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