I tried HackerRank’s Project Euler Problem #1: Multiples of 3 and 5:
Project Euler #1

My code is in Java. I tried to solve this using recursion:

public class Solution {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int cases = scanner.nextInt();
        for (int i = 0; i < cases; i++) {
            int n = scanner.nextInt();
            int sum = calculateSum((n % 3 == 0) ? n - 3 : n - (n % 3), 3) + 
                    calculateSum((n % 5 == 0) ? n - 5 : n - (n % 5), 5) - 
                    calculateSum((n % 15 == 0) ? n - 15 : n - (n % 15), 15);
            System.out.println(sum);
        }
    }
    
    private static int calculateSum(int n, int f) {
        if (n <= 0) {
            return 0;
        }

        return  n + calculateSum(n - f, f);
    }
}

It shows runtime error for hidden cases 2 and 3:
Test Cases Result