Answer 1

Using Euclid's formula:

http://code.sololearn.com/c9TT4MM7L4ic

public class Program {
public static void main(String[] args) {
int count = 0;
for (int m = 2; count < 15; m++) {
for (int n = 1; (count < 15)&&(n < m); n++) {
int a = m*m - n*n;
int b = 2*m*n;
int c = m*m + n*n;
System.out.println("(" + a + ", " + b + ", " + c + ")");
count++;
}
}
}
}