The Millin series is defined as:
$$\sum_{n \mathop = 0}^\infty \frac 1 {F_{2^n} }$$
where $F_n$ denotes the $n$th Fibonacci number.
It can be shown to equal $\dfrac {7 - \sqrt 5} 2$.
But who was the D.A. Millin who it is named after?
EDIT: User https://hsm.stackexchange.com/users/16591/michael has located the issue of FQ in which Millin's name originally appears, where he was identified as a Pennsylvanian high-school student in 1974.
Further to this, I have found that the solution appeared in FQ issue Vol. 14 no. 2 (1976), but in this case his name appears as D.A. Miller.
The question arises as to whether Millin might have been a misprint. If his name truly is "Miller", then his precise identity may be very difficult to track down. There is a professor in Virginia with that name, but he appears a couple of decades too young.
Whoever he is, he may well be currently active.