4 ms·

If n=8, then this function equals 25. Am I missing something?

• stillbourne 11y ago
  Yeah, its a sieve, this block: foreach (@k){ my $b = $_; my $n = "1"; $c=1; next if ($b >= floor(sqrt($y + 1))); for ($count = $y + 1 ;$count >= $c; $n++){ $c = (((3 * $n) - (0.5 * cos($pi*$n))) + 1.5) * $b; next unless ($c <= $y + 1); push (@c, $c); } } Allows you to iterate of the next set and find the none prime and remove them from the SET of 1/2 (6 n-cos(pi n)+3) Thats how a sieve works. 1/2 (6 n-cos(pi n)+3) is only good up to n^2 then you need to multiply 1/2 (6 n-cos(pi n)+3) by i as you noted the first non-prime result was @ 5^2 therefore you need to sieve the rest of the numbers up to 7^2 by doing (1/2 (6 n-cos(pi n)+3)) * 5 Then after 7^2 seive off with (1/2 (6 n-cos(pi n)+3)) * 7 you continue to repeat this for all numbers in the original set. See the sieve of eratosthenes. Mine though shows primes as a set of sin waves kind of like what the op has. As a matter of fact the post is basically a visual representation of what I coded above.