using java to implement binomial coefficient

Binomial.java

public class Binomial
{
    public static int[][] binomial(int N)
    {
	int[][] a = new int[N+1][N+1];

	for (int i = 1; i <= N; i++)
	    for (int j = 1; j <= i; j++)
		{
		    if (i == j)
			a[i][j] = 1;
		    else
			a[i][j] = a[i-1][j] + a[i-1][j-1];
		}
	return a;
    }
    public static boolean[][] isOdd(int[][] a)
    {
	int N = a.length;
	boolean[][] b = new boolean[N][N];
	for(int i = 1; i < N; i++)
	    for(int j = 1; j < N; j++)
		if(a[i][j] == 0)
		    b[i][j] = false;
		else if(a[i][j] % 2 == 0)
		    b[i][j] = true;
	return b;
	
    }
    public static void main(String[] args)
    {
	int N = Integer.parseInt(args[0]);
	int[][] b = binomial(N);
	boolean[][] c = isOdd(b);
	RelativePrime.show(c);
    }
}