When writing an electron configuration in orbital form, you put the last noble gas configuration in front, for vanadium it's (Ar). The s-block is filled with its capacity of 2 electrons since vanadium is a regular transition metal. The first d subshell, 4d, puts electrons into the 3rd shell not the outer shell. So it has 2 valence electrons. The exceptions to this rule are chromium, molybdenum, copper, silver and gold, which put one of the s electrons into the d shell.