Solution:
We have 13+23+⋯+163=(1+2+⋯+16)2=1362.
So, 13+23+⋯+163+17n=1362+17n.
We want 1362+17n to be a perfect square.
Let 1362+17n=k2 for some integer k.
Then k2−1362=17n, so (k−136)(k+136)=17n.
Since 17 is prime, both k−136 and k+136 must be powers of 17.
Let k−136=17a, k+136=17b, with a<b, a+b=n.
Then k+136−(k−136)=272=17b−17a.
So 272=17a(17b−a−1).
Now, 17a divides 272. Since 272=16×17, the possible values for a are 0 and 1.
Case 1: a=0
Then 17b−0−1=272, so 17b=273, which is not possible.
Case 2: a=1
Then 171(17b−1−1)=272, so 17b−1−1=16, so 17b−1=17, so b−1=1, b=2.
So a=1, b=2, n=a+b=3.
Therefore, the only solution is n=3.
Check:
13+23+⋯+163+173=1362+4913=18496+4913=23409=1532, which is a perfect square.
Thus, the only positive integer n for which 13+23+⋯+163+17n is a perfect square is n=3.