text: Main part of Sieve of Atkin
code: let n = ( 4 * x * x ) + ( y * y ) ; if ( n <= limit && ( n % 12 == 1 n % 12 == 5 ) ) sieve [ n ] ^= true ; n = ( 3 * x * x ) + ( y * y ) ; if ( n <= limit && n % 12 == 7 ) sieve [ n ] = true ; n = ( 3 * x * x ) - ( y * y ) ; if ( x > y && n <= limit && n % 12 == 11 ) sieve [ n ] ^= true ; } }