Testing for int/sqrt glitch

Question

I am working on a homework assignment that involves getting all values of a and b in range x, and then finding r (a^2 + b^2)/(a*b+1). I need to omit all data r which are not ints and not square roots. I have made a function to omit each, neither work. Here is the code:

/**
 * Compiler to use: javac
 * Name: Mike Fitzgibbon
 * Date: 9/16/2022
 * Class: CS4500
 * 
 * Sources used:
 * I used this one to remind me where the .floor() method was
 * https://www.programiz.com/java-programming/library/math/floor#:~:text=The%20floor()%20method%20rounds,is%20equal%20to%20integer%203.
 */

package mikefitzgibbon.cs4500hw3;

import java.util.ArrayList;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        int x = getX();
        ArrayList<Double> data[] = generateABR(x);
        data = rIsInt(data);
        data = rIsSquare(data);
        printData(data);
    }
    
    //gets the user input
    private static int getX(){
        Scanner scanner = new Scanner(System.in);
        int x=0;
        boolean xValid = false;
        
        //message to get X
        System.out.println("Please enter an integer 1-100000.");
                
        while(!xValid){
            //get int and make sure it's an int
            String s = scanner.next();
            try{
                x = Integer.parseInt(s);

                //test to make sure x is from 0 to 100000 inclusive
                if(x < 1 || x > 100000){
                    System.out.println("X is not withing the valid range of 1-100000.");
                }
                else xValid = true;
            }
            catch(NumberFormatException e){
                System.out.println("You did not enter an integer.");
            }
        }
        
        return x;
    }
    
    //creates 3 ArrayLists with a, b, and r as the values
    private static ArrayList<Double>[] generateABR(int x){
        //initialize the data structure that will store the variables
        ArrayList<Double> data[] = new ArrayList[3];
        data[0] = new ArrayList<>();//a
        data[1] = new ArrayList<>();//b
        data[2] = new ArrayList<>();//r
        
        //find all pairs of a and b within range x
        for(int a = 1 ; a <= x ; a++){
            for(int b = 1 ; b <= x ; b++){
                data[0].add((double)a);
                data[1].add((double)b);
                //r's formula
                data[2].add((Math.pow(a, 2) + Math.pow(b, 2)) / 
                        (a * b + 1.0));
            }
        }
        
        return data;
    }
    
    //filters out r's that are not ints
    private static ArrayList<Double>[] rIsInt(ArrayList<Double> data[]){
        for(int a = 0 ; a < data[0].size() ; a++){
            //if r of data set is not an int, delete from data structure
            if(data[2].get(a) % 1 != 0){
                data[0].remove(a);
                data[1].remove(a);
                data[2].remove(a);
            }
        }
        
        return data;
    }
    
    //filters out r's that aren't perfect squares
    private static ArrayList<Double>[] rIsSquare(ArrayList<Double> data[]){
        for(int a = 0 ; a < data[0].size() ; a++){
            //if r of data set is not a perfect square, delete from data structure
            if(Math.sqrt(data[2].get(a)) % 1 != 0){
                data[0].remove(a);
                data[1].remove(a);
                data[2].remove(a);
            }
        }
        
        return data;
    }
    
    //prints out the data
    private static void printData(ArrayList<Double> data[]){
        for(int a = 0 ; a < data[0].size() ; a++){
            System.out.println("A: " + Math.round(data[0].get(a)) + " B: " + Math.round(data[1].get(a)) + " R: " + data[2].get(a));
        }
    }
}

and here is an example session:

Please enter an integer 1-100000.
3
A: 1 B: 1 R: 1.0
A: 2 B: 2 R: 1.6
A: 3 B: 3 R: 1.8

The lines with 1.6 and 1.8 should have been removed. So the expected output in this case would be only one line:

A: 1 B: 1 R: 1.0