Numbers n such that phi(sigma(n)) + phi(phi(n)) = n.

Terms

a(0) =3a(1) =28a(2) =108a(3) =2352a(4) =2544a(5) =7936a(6) =13632a(7) =26736a(8) =209904a(9) =256608a(10) =1394112a(11) =2052864a(12) =2169456a(13) =2490864a(14) =11942400a(15) =18884416a(16) =258072480a(17) =415272960a(18) =2064579840a(19) =3737456640a(20) =3963371520a(21) =4672512000