Numbers n such that phi(phi(n)) + sigma(sigma(n)) is an 8th power.

Terms

a(0) =42a(1) =101a(2) =6720a(3) =9212a(4) =226570a(5) =276404a(6) =288086a(7) =299668a(8) =339098a(9) =392228a(10) =412276a(11) =423395a(12) =530917a(13) =535759a(14) =559427a(15) =564209a(16) =666181a(17) =2835284a(18) =3592300a(19) =3911744a(20) =4080100a(21) =5980673a(22) =7230960a(23) =8787900a(24) =14960924a(25) =17130550a(26) =23324242a(27) =27449729a(28) =30437729a(29) =33869141