Its indefinite: Start with 0,1 add last two numbers = 1 add to sequence = 0,1,1 add last two numbers = 2 add to sequence = 0,1,1,2 add last two numbers = 3 add to sequence = 0,1,1,2,3 add last two numbers = 5 add to sequence = 0,1,1,2,3,5 add last two numbers ......... add to sequence ..........