C :

#include<stdio.h>
int isprime(int i)
{
	int j;
	if(i == 0 || i == 1) return 0;
	if(i == 2 || i == 3 || i == 5 || i == 7 || i == 11) return 1;
	if(i%2 == 0 || i%3 == 0 || i%5 == 0 || i%7 == 0 || i%11 == 0) return 0;
	for(j=12; j*j<=i;j++)
	if(i%j==0)
	return 0;
	return 1;
}
int main()
{
	int a,b,c;
	scanf("%d%d",&a,&b);
	int i,j;
	for(i=a;i<=b;i++)
	{
		printf("%d=",i);
		if(isprime(i))
		printf("%d\n",i);
		else
		{
			for(j=2,c=i;;j++)
			{
				if(c%j==0)
				{
					printf("%d*",j);
					c=c/j;
					j=1;
				}
				if(isprime(c))
				{
					printf("%d\n",c);
					break;
				}
			}
		}
	}
}

C++ :

#include<iostream>
#include<cmath>
using namespace std;

int is_prime(int n)
{
	for(int i = 2; i*i <= n; i++)
	{
		if(n % i == 0) 
		{
			return 0;
		}
	}
	return 1;
} 

int prime[10000], count = 0;

int main()
{
    int a, b; 
    int flag = 0;
	for(int i = 2; i <= 10000; i++)
	{
		if(is_prime(i)) prime[count++] = i;
	}
	cin >> a >> b;
	for(int j = a; j <= b; j++)
	{
		flag = 0;
		cout << j << "=";
		int m = j;
		for(int k = 0; k < count; k++)
		{
			while(m%prime[k] == 0)
			{
				m /= prime[k];
				flag++;
				if(flag == 1) cout << prime[k];
				else cout << "*" << prime[k];
			}
		}
		cout << endl; 
	}
	return 0;
} 

Pascal :

program p23699;
 var a,b,i,j,n,t,p:longint;
 fj: array[1..100] of longint;
begin
 readln(a,b);
 for i:= a to b do
  begin
   write(i,'=');
   n:=i;
   p:=0;
   t:=2;
   while(n>1) do
    begin
     while(n mod t=0)do
      begin
       inc(p);
       fj[p]:=t;
       n:=n div t;
      end;
      inc(t);
    end;
   for j:=1 to p do
    if j<p then
     write(fj[j],'*')
    else
     writeln(fj[j]);
  end;
end.