(In reply to
An interesting reference by broll)
Euler conjectured that at least n n-th powers are required for <IMG class=inlineformula border=0 alt="n>2" src="http://mathworld.wolfram.com/images/equations/EulersSumofPowersConjecture/Inline3.gif" width=29 height=14> to provide a sum that is itself an n-th power.
Please edit your 3rd-from-the-bottom line: fifth into k-th.