Ulam numbers that are fourth powers.

Terms

a(0) =1a(1) =16a(2) =1296a(3) =20736a(4) =160000a(5) =390625a(6) =3748096a(7) =8503056a(8) =16777216a(9) =62742241a(10) =193877776a(11) =429981696a(12) =623201296a(13) =855036081a(14) =1766100625a(15) =1871773696a(16) =1982119441a(17) =2562890625a(18) =2947295521