What is the chromatic polynomial P(Cn,k)P(C_n, k)P(Cn,k) for a cycle graph CnC_nCn?
kn−kk^n - kkn−k
(k−1)n+(−1)n(k−1)(k-1)^n + (-1)^n (k-1)(k−1)n+(−1)n(k−1)
k(k−1)n−1k(k-1)^{n-1}k(k−1)n−1
knk^nkn