Odd solutions of phi(sigma(k)) = sigma(phi(k)).

Terms

a(0) =1a(1) =9a(2) =225a(3) =729a(4) =18225a(5) =65025a(6) =140625a(7) =531441a(8) =5267025a(9) =11390625a(10) =13286025a(11) =18792225a(12) =40640625a(13) =87890625a(14) =1522170225a(15) =2197265625a(16) =3291890625a(17) =3839661225a(18) =5430953025a(19) =7119140625a(20) =8303765625a(21) =11745140625a(22) =25400390625