Here are a few examples of bounded sequences of length 8, starting with1:
(1, 2, 3, 4, 3, 2, 1,0), (1, 2, 1, 2, 1, 2, 1, 2), (1, 0, -1, -2, -3, -4, -3, -2)
How many bounded sequences of length n have first and last element 0?