Numbers k such that k + sigma(k) + phi(k) is a fourth power.

Terms

a(0) =81a(1) =18904a(2) =176705a(3) =204576a(4) =534160a(5) =1362561a(6) =1366633a(7) =1698256a(8) =1866768a(9) =2034576a(10) =2523024a(11) =2909656a(12) =3380856a(13) =7217649a(14) =9439473a(15) =9454609a(16) =11197696a(17) =12866040a(18) =29508673a(19) =32363424a(20) =34142545a(21) =34682089a(22) =46426160a(23) =46448824a(24) =53445456a(25) =57807984a(26) =58298881a(27) =81378529a(28) =98156353