Saouter number

A Saouter number is a type of Generalized Fermat number. Numbers of this type have the form

$A_n=4^{3^n}+2^{3^n}+1$

In the notation of John Cosgrave, the Saouter numbers are generated by the sequence $F_{n,2}$. Due to this, these numbers share similar properties to those held by Fermat numbers. These numbers were named by Tony Reix after Yannick Saouter, who studied these numbers.