What is the next number in the sequence below?

Answer is 49

1 * 1 = 1 2 * 2 = 4 3 * 3 = 9 4 * 4 =16 5 * 5 = 25 6 * 6 = 36 7 * 7 = 49

What is the next number in the matchsticks number sequence below?