Compute i600+i599+....+i+1=1. Where i2=−1.
I assume this is supposed to be600∑k=0ik
The sum of any 4 adjacent terms of this series is 0.
600 is divisible by 4.
There are 601 terms, 600 of which will sum to zero leaving the last (or first) term i600 = i0 = 1
