Abstract
Using the group consisting of the eight Möbius transformations x, – x, ,
,
, and
, we present an enumerative proof of the classical result for when the element 2 is a quadratic residue in the finite field Fq
.
Acknowledgmenst
The authors thank David Leep for suggestions that improved the exposition of an earlier version of this note. This work was partially supported by a grant from the Simons Foundation (#429370 to Richard Ehrenborg).