recursive function to find the sum of the nth term

void recurse() {
    .....
    recurse()  //recursive call
    .....
}
int main() {
    .....
    recurse(); //function call
    .....
}

#include <stdio.h>
int addNumbers(int n);
int main() {
    int num;
    printf("Enter a positive integer: ");
    scanf("%d", &num);
    printf("Sum = %d", addNumbers(num));
    return 0;
}

int addNumbers(int n) {
    if (n != 0)
        return n + addNumbers(n - 1);
    else
        return n;
}