Numbers of the form (4^(p^(k+1)) + 1)/(4^(p^k) + 1), where k >= 1 and p is an odd prime other than 5.

A371757

Numbers of the form (4^(p^(k+1)) + 1)/(4^(p^k) + 1), where k >= 1 and p is an odd prime other than 5.