For which nnn is (1+i)n(1+i)^n(1+i)n a purely imaginary number?
n=4k+1n = 4k+1n=4k+1
n=4k+2n = 4k+2n=4k+2
n=4k+3n = 4k+3n=4k+3
n=2k+1n = 2k+1n=2k+1