Hello I have been asked to find a formula of how many different Euler circuits or as it also called eulerian cycles are in $K_{2,n}$. when $n$ is an even number ofcourse otherwise there won't be any eulerian circuits.
for example in $K_{2,2}$ you have vertices $a$ $b$ $c$ $d$ so there is only one cycle possible, in other words $adbca$ is the same as $cbdac$.
thanks from advance :)