Need help with emirp problem.

I have two problems. First, the output has single digit numbers in it which I believe makes them not emirps (because they are the same backwards and forwards). The second problem I'm having is in formatting. I tried several variations of the printf(%3d, n) variety and could not get them to format properly. It has to be the 1st 100 emirps, 10 per line, each row right justified. The example output is:

13 17 31 37 71 73 79 97 107 113

149 157 167 179 199 311 337 347 359 389

Any help would be greatly appreciated.

Re: Need help with emirp problem.

Forgot to put my code in there:

public class Exercise05_27 {

public static void main (String [] args) {

int count=0;

int n=2;

while (count<100){

if (isEmirp(n)){

System.out.print(n+" ");

count++;

if (count%10==0)System.out.println();

}

n++;

}

}

public static boolean isPrime(int n){

for(int i=2; i<=n/2; i++){

if(n%i==0)return false;

}

return true;

}

public static boolean isEmirp(int n){

return isPrime(n) && isPrime(reverseDigits(n));

}

public static int reverseDigits(int n){

if (n<10) return n;

return recursiveHelper(n%10,n/10);

}

public static int recursiveHelper(int p, int q){

if(q<1) return p;

return recursiveHelper(p*10+q%10,q/10);

}

}

Re: Need help with emirp problem.

Okay, I just looked at the output I typed in and it isn't formatted the way I typed it. It should be all lined up, 10 per line, each column right justified.