Prime powers (A025475) representable as (p+q)/2, where p and q are distinct prime powers.

Terms

a(0) =25a(1) =125a(2) =169a(3) =243a(4) =256a(5) =289a(6) =625a(7) =841a(8) =1369a(9) =1681a(10) =2809a(11) =3125a(12) =3721a(13) =5329a(14) =9409a(15) =11881a(16) =12769a(17) =18769a(18) =22201a(19) =28561a(20) =37249a(21) =38809a(22) =54289a(23) =76729a(24) =83521a(25) =100489a(26) =113569a(27) =151321a(28) =160801a(29) =196249