The outer Soddy center (or outer Soddy point) is the center of the outer Soddy circle. It is equivalent to the isoperimetric point (Kimberling 1994) and has equivalent triangle center functions
where is the circumradius of the reference triangle.
It lies on the Soddy line.
More things to try:
Weisstein, Eric W. "Outer Soddy Center." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/OuterSoddyCenter.html
(Kimberling 1994) and has equivalent triangle center functions
is the circumradius of the reference
triangle.
