The Hamming Cube of dimension n is the graph whose vertices are all binary strings of length n and there is an edge from u to v if the strings at u and v differ in exactly on place, and is denoted H_n. For example, there would be an edge from 0110 to 0111 in H_4. How many vertices and edges does H_n have, for general n? Does H_17 have an Eulerian cycle