Hello,
I wonder why make n = 2 x 7 = 14. Thank you.
If n = 14, notice that
504n
=504 \times 14
=(2^3 \times 3^2 \times 7) \times (2 \times 7)
=2^4 \times 3^2 \times 7^2
Can you see why that must be a perfect square?
Yes. Each number has to be even power to get the perfect square. Thank you.