import java.util.Arrays;
import java.util.stream.IntStream;

class Teste {
    public static void main(String[] args) {
        int[] numeros = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20};
        int[] quadrados = IntStream.of(numeros).map(x -> x * x).toArray();
        System.out.println(Arrays.toString(quadrados));
    }
}