Challenge: find the first value where two functions differ

[Chris Angelico]

On Sat, Aug 5, 2017 at 1:44 AM, Chris Angelico <rosuav at gmail.com> wrote:
> That gave me this result almost instantaneously:
>
> 4503599761588224
>
> which has been rounded up instead of down. I don't know if that counts
> as sufficiently wrong?

Oh, and I forgot to say: I have no actual *proof* that this is the
lowest number for which this will occur. It does not occur with
4503599761588223 (the next lower integer), but could happen with
something between two squares, for all I know. However, I suspect that
it wouldn't.

ChrisA