Dynamic memory allocation confusion

Question

I saw a tutorial where the instructor dynamically allocates memory for n*int size (n is not known in advance, user would give it as an input). Just out of curiosity, I have changed the code from calloc(n,sizeof(int)) to calloc(1,sizeof(int)) and I was expecting to see an error, but I did not face an error, and the code runs smoothly.

If I increment the pointer and it just continues without a problem, why should I use anything else but calloc(1,sizeof(int))?

#include <iostream>

using namespace std;

int main(){

    int n;
    printf("enter the size of array\n");
    scanf("%d",&n);
    int* A = (int*)calloc(1,sizeof(int));

    for(int i=0; i<n; i++){

        *(A+i) = i+1;
    
    }

    for(int i=0; i<n; i++){

        printf("%d\n", A[i]);
        printf("%d\n", &A[i]);
    }

    // free(A)

    return 0;
}