Array pointer arithmetic in C

Pointers.c

int main(int argc, char *argv[])
{
  int *arr;
  arr = malloc(5);

  arr[0] = 1;
  arr[1] = 10;
  arr[2] = 20;
  arr[3] = 30;
  arr[4] = 40;
  
  printf("address first value: %p\n", arr);
  printf("first value: %d\n\n", *arr);

  for (int i = 0; i < 5; i++)
  {
    printf ("arr[%d]   address:\t\t%p\n", i, arr + i);
    printf ("arr[%d+1] address:\t\t%p\n", i, arr + i + 1);
    printf ("arr[%d+1] address char cast:\t%p\n", i, ((char *) (arr + i)) + 1);
    printf ("\n");
  }

  free(arr);
  return 0;
}