import java.util.Scanner; import java.lang.Math; // This is no longer needed if we remove Math.pow

class Test { public static void main(String[] args) { Scanner scn = new Scanner(System.in); int q = scn.nextInt();

    // The outer 'if' check is not needed.
    // A 'for' loop with q=0 will just not run, which is correct.
    for(int i = 0; i < q; i++) { // Using i=0; i<q is the more common Java convention
        int a, b, n;
        a = scn.nextInt();
        b = scn.nextInt();
        n = scn.nextInt();

        // The inner 'if' check is also not needed for HackerRank

        int series = a;

        for(int j = 0; j < n; j++) {
            // Use (1 << j) instead of Math.pow(2, j)
            // It's faster and works directly with integers.
            series += (1 << j) * b; 
            System.out.print(series + " ");
        }
        System.out.println();
    }

    // Good practice to always close the scanner!
    scn.close(); 
}

}

Java Optimal Code (100% beats) #java #coding

import java.io.; import java.util.;

public class Solution {

public static void main(String[] args) {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution. */
    Scanner scn = new Scanner(System.in);
    int q = scn.nextInt(); // q represent number of series u want to print

    for(int i = 1; i <= q; i++) {
        int a, b, n;

        a = scn.nextInt(); //First element in the series
        b = scn.nextInt(); //Second element in the series
        n = scn.nextInt(); // number of elements in the series

        int series = a; // we initialize with a to avoid multiple addition
                        // of a in the main logic 

        // j represent the exponential of base case (b^e)
        for(int j = 0; j < n; j++){
            //main logic
            //(1<<j) is the fast way to get 2^j
            series += (1<<j) * b;
            System.out.print(series + " ");
        }
        System.out.println();
    }

}

}

import java.io.; import java.util.;

public class Solution {

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int q = sc.nextInt();

    for (int i = 0; i < q; i++) {
        int a = sc.nextInt();
        int b = sc.nextInt();
        int n = sc.nextInt();
    if (q>=0 && q<=500) {
        int series = a;
        for (int j = 0; j < n; j++) {
            series = series + (int)Math.pow(2,j) * b;
            System.out.print(series + " ");
        }
        System.out.println();
    }
    }
}

}

For Java15 Platform

I wrote the code from scratch just to get more practice

import java.util.Scanner;

class Solution
{
    public static void main(String args[])
    {
        Scanner sc = new Scanner(System.in);
        int q = sc.nextInt();
        
        for(int i=0; i<q; i++)
        {
            int a, b, n;
            a = sc.nextInt();
            b = sc.nextInt();
            n = sc.nextInt();
            
            int series = a;
            
            for(int j=0; j<n; j++)
            {
                series += Math.pow(2, j) * b;
                
                System.out.print((int)series + " ");
            }
            
            System.out.print("\n");
        }
        
        sc.close();
    }
}

Java

Solution using Map for memoization for better performance

public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        sc.nextLine();
        while(sc.hasNextLine()){
            String[] linea = sc.nextLine().split(" ");
            int a = Integer.parseInt(linea[0]); 
            int b = Integer.parseInt(linea[1]);
            int n = Integer.parseInt(linea[2]);
            
            // Create a map in order to save previously calculated values
            Map<Integer, Double> map = new HashMap<>();
            StringBuilder sb = new StringBuilder();
            
            map.put(0, Math.pow(2, 0)*b);
            for(int i = 1; i < n; i++){
                map.put(i, map.get(i-1) + Math.pow(2, i)*b);
            }
            map.values().forEach(v -> sb.append( a + Math.round(v) +" "));
            System.out.println(sb.substring(0, sb.length()-1))    ;
            
        }
        sc.close();
    }