XO hashCode, more general

 public static Random rand = new Random();
 private final int[] primes = calcPrimes(DIM, DIM);

 @Override
 public int hashCode(){

   int result = 1;

   for(int i = 0; i < DIM; i++){
     for(int j = 0; j < DIM; j++){
       result += (tabla[i][j] + 3) * primes[i + j];
     }
   }

   return result;
 }

 private int[] calcPrimes(int d1, int d2){
   final int d = d1 * d2;
   int[] result = new int[d];

   for(int i = 0; i < d; i++){
     //Increasing the value(to some number)
     //will improve in results
     result[i] = getPrime(50);
   }

   return result;
 }

 private int getPrime(int t){
   int result = 1;
   while(true){
     int r = rand.nextInt(t);
     if(isPrime(r)){
       return r;
     }
   }
 }

 public static boolean isPrime(int n){

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

   return true;
 }