Java - Problema a la hora de ejecuar un array desigual

public class LotteryArray
{
public static void main(String[] args)
{
final int NMAX = 10;
int[][] odds = new int[NMAX + 1][];
for (int n = 0; n <= NMAX; n++)
odds[n] = new int[n + 1];
for (int n = 0; n < odds.length; n++)
for (int k = 0; k < odds[n].length; k++)
{
int lotteryOdds = 1;
for (int i = 1; i <= k; i++)
lotteryOdds = lotteryOdds * (n -i + 1) / i;
odds[n][k] = lotteryOdds;
}
for (int n = 0; n < odds.length; n++)
{
for (int k = 0; k < odds.length; k++)
{
String output = " " + odds[n][k];
output = output.substring(output.length() - 2);
System.out.print(output);
}
System.out.println();

}
}
}

Hola alguien me podria ayudar tengo este codigo y a la hora de ejecutarlo me muestra el siguiente error les agradeceria me ayudaran lo mas pronto posible me urge.

Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String ind
ex out of range: -2
at java.lang.String.substring(String.java:1474)
at java.lang.String.substring(String.java:1447)
at LotteryArray.main(LotteryArray.java:24)

for (int n = 0; n < odds.length; n++)
{
for (int k = 0; k < odds[n].length; k++)
{