$F_{15}$
$${\rm LOG}\left(F_{15}\right)=\frac{2}{15}\pi
\left[\begin{array}{rrrrrrrrrrrrrrr}
\bullet & \bullet & \bullet & \bullet & \bullet & \bullet & \bullet & \bullet & \bullet & \bullet & \bullet & \bullet & \bullet & \bullet & \bullet\\
\bullet & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 & {10} &{11} &{12} & {13} & {14}\\
\bullet & 2 & 4 & 6 & 8 & {10} & {12} & {14} & 1 & 3 &5 &7 & 9 & {11} & {13}\\
\bullet & 3 & 6 & 9 & {12} & \bullet & 3 & 6 & 9 & {12} & \bullet &3 &6 & 9 & {12}\\
\bullet & 4 & 8 & {12} & 1 & 5 & 9 & {13} & 2 & 6 &{10} &{14} & 3 & 7 & {11}\\
\bullet & 5 & {10} & \bullet & 5 & {10} & \bullet & 5 & {10} & \bullet & 5 &{10}& \bullet & 5 & {10}\\
\bullet & 6 & {12} & 3 & 9 & \bullet & 6 & {12} & 3 & 9 & \bullet &6 &{12} & 3 & 9\\
\bullet & 7 & {14} & 6 & {13} & 5 & {12} & 4 & {11} &3 &{10} & 2 & 9 & 1 & 8\\
\bullet & 8 & 1 & 9 & 2 & {10} & 3 & {11} & 4 & {12} &5 &{13} & 6 & {14} & 7\\
\bullet & 9 & 3 & {12} & 6 & \bullet & 9 & 3 & {12} & 6 & \bullet &9 &3 & {12} & 6\\
\bullet & 10 & 5 & \bullet & {10} & 5 & \bullet & {10} & 5 & \bullet &{10} & 5& \bullet & {10} & 5\\
\bullet & 11 & 7 & 3 & {14} & {10} & 6 & 2 & {13} &9 & 5& 1 & {12} & 8 & 4\\
\bullet & 12 & 9 & 6 & 3 & \bullet & {12} & 9 & 6 & 3 & \bullet &{12}& 9 & 6 & 3\\
\bullet & 13 & {11} & 9 & 7 & 5 & 3 & 1 & {14} & {12}&{10} & 8 & 6 & 4 & 2\\
\bullet & 14 & {13} & {12} & {11} & {10} & 9 & 8 & 7 &6 & 5 & 4 & 3 & 2 & 1
\end{array}\right]$$