Error in the output when extracting an int from a two-dimensional array in C

Hi, I have the following code that performs the calculation of a combinational number:

int combinacional(int_pair par) {
int i,j;
int tabla[par.a+1][par.b+1] ;

if(par.b == 0 || par.b == par.a) {
   return 1;
}
else if (par.b == 1 || par.b == (par.a - 1)) {
    return par.a;
}
else {
   for (i=0; i<=par.a; i++) {
     tabla[i][0] = 1;
   }

   for (i=1; i<=par.a; i++) {
     tabla[i][1] = i;
   }

   for (i=2; i<=par.b; i++) {
     tabla[i][i] = 1;
   }

   for (i=3; i<=par.a;i++) {
     for (j=2; j<par.a; j++) {
       if(j<=par.b) {
         tabla[i][j] = tabla[i-1][j-1] + tabla[i-1][j];
       }
     }
   }
   }

   return tabla[par.a][par.b];
}

In it I make use of "int_pair" which would be an equivalent to a tuple in which the first or second value can be selected, I also create a two-dimensional array to be able to store the values ​​of the Pascal triangle and take the result of this at the end . The error comes when displaying the output, for this I use the following:

void test() {
list enteros = leerFichero4("ficheros/entradaE4.txt");

for (int i = 0; i < enteros.size; i++) {
    int_pair tupla = *(int_pair*) list_get(&enteros, i);
    int result = combinacional(tupla);
    printf("Entrada = %s; ", int_pair_tostring(&tupla, mem));
    printf("Salida = %i\n", result);
    printf("========================================\n");
}
}

int main() {
   test();
}

This shows me the following:

Entrada = (10,1); Salida = 10
========================================
Entrada = (9,2); Salida = 36
========================================
Entrada = (8,3); Salida = 7105
========================================
Entrada = (7,4); Salida = -996404052
========================================
Entrada = (6,5); Salida = 6
========================================

The first two outputs and the last one are correct. However, the others must be 56 and 35 and pointers to memory locations appear, I imagine. I guess it's some pointer error but I can't find it.