Let $G$ be the graph in picture:
calculate the chromatic polynomial of it.
I assume that $G(K_n,x)$ is the number of distinct colors of the complete graph with $n\geq1$ vertices with at most $x$ colors. So, in case of a classic square it'll be:
$G(K_4,x) = x(x-1)(x-2)(x-3) = x^4-6x^3+11x^2-6x$
but here we have one more edge between two nodes. What should I do?