# 3 , 2+1, 1+1+1

Discrete Mathematics Level 2

The number 3 can be written as 3 , 2+1 , 1+2 , 1+1+1, which is a total of four ways. Note that the order of summands in important. If the number of ways in which the number n be written is a, what is the value of 2a?

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