C :

#include<stdio.h>
int a[100001];
main()
{
	int n;
	scanf("%d",&n);
	int i,j;
	for(i=1;i<=n;i++)
	{
		for(j=i;j<=n;j++)
		{
			if(j % i==0)
			{
				a[j]++;
			}
		}
	}
	for(i=1;i<=n;i++)
	{
		if(a[i]%2==1)printf("%d ",i);
	}
	return 0;
}

C++ :

#include<iostream>
#include<iomanip>
#include<cstring>
//#include<ctime>
#include<cstdio>
using namespace std;
int main()
{
	//freopen("test3.in","r",stdin);
	//freopen("test3.out","w",stdout);
	int n,i,j;
	bool a[1000000];
	memset(a,true,sizeof(a));
	cin>>n;
	for(i=2;i<=n;i++)
	  for(j=i;j<=n;j++)
	    if(j%i==0)a[j]=!a[j];
	for(i=1;i<=n;i++)
	  if(a[i]) cout<<i<<' ';
	cout<<endl;
	//printf("%0.3f",float(clock())/1000);
	return 0;
}

Pascal :

var 
    f:array[0..100001] of boolean;
	i,j:longint;
    n:longint;
begin
	readln(n);
       fillchar(f,sizeof(f),0);
        for i:= 1 to  n do
	    for j:= 1 to n div i do
		f[i * j] := not f[i * j];
        for i:= 1 to n do
          if (f[i]) then write(i,' ');
    writeln;
end.

Python :

n = int(input())
for i in range(1,n,1) :
    if i*i <= n :
        print i*i ,
    else :
        break

print '\n'