import std.stdio:write; import std.algorithm:uniq; import std.array:array; ulong[] prime_factors(ulong n) { ulong c = 2; ulong[] arr; while(n > 1) { if(n % c == 0) { arr ~= c; n /= c; } else c++; } return arr; } void square_free_integers() { ulong i = 1; do{ ulong[] primes = prime_factors(i); ulong prime = primes.uniq().array.length; if(primes.length - prime == 0) write(i, ' '); i++; }while(i <= 500); } void main() { square_free_integers(); }