Stuck with using lists to solve task

[Gribouillis]

I'm interested in the result, so here is my solution (True = open),
Anybody. ?

I think the result is True if the number of divisors of n is odd. The number of divisors of a number is given by the sequence https://oeis.org/A000005. This page says

a(n) is odd iff n is a square.

All of this needs to be clarified.

This page also contains a python code that uses sympy to get the number of divisors of a number.