Highest Power of 2 Dividing Numerator of Sum of Odd Reciprocals/Historical Note

Historical Note on Highest Power of 2 Dividing Numerator of Sum of Odd Reciprocals
This result was posed as an elementary problem by in March $1960$:.

He notes that and  leave the problem unsolved in an article in a $1959$ commercial publication, where they suggest that:
 * an estimate [of this] power of $2$ ... seems in general to be a difficult number theoretic problem.

In the event, $7$ contributors are reported as having submitted a solution, of which that by was the one published.

Among the solvers was, who included the problem as an exercise of difficulty level $M33$ in his.