Guess the Periodic Signal
A certain periodic signal has the following properties:
1. N = 6
2. $ \sum_{n=0}^{4}x[n] = 4 $
3. $ \sum_{n=1}^{5}(-1)^nx[n] = 2 $
4. $ a_k = a_{k+3}\, $
Answer
From 1. we know that $ x[n] = \frac{1}{6}\sum_{n=0}^{4}a_k e^{jk\frac{\pi}{3}n}\, $
