17*. For what values of the natural number \(n\) is the sum \(n^{2}+\) \(+(n+1)^{2}+(n+2)^{2}+(n+3)^{2}\) divisible by ten?
17. \(n=5 k+1, k=\{0 ; 1 ; 2 ; \ldots\}\). Hint. Show that the last digit of the decimal representation of the number \(n\) can only be 1 or 6.