I came across the following conjecture, reading a recent paper in the Monthly, an orthogonal matrix of order $n\neq 0 \pmod 4$ has a nonnegative (up to a scalar) rawrow vector. It should be straight in in dimensions $2$ and $3$ and much impossible for the rest. Do that make any relation within certain result.
Post Closed as "Needs details or clarity" by Alexandre Eremenko, Ben McKay, Joonas Ilmavirta, user44191, Chris Godsil
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