Numbers whose arithmetic derivative is equal to Euler totient function: n' = phi(n).

Terms

a(0) =2a(1) =9a(2) =15a(3) =625a(4) =1225a(5) =3993a(6) =117649a(7) =218491a(8) =857375a(9) =3788435a(10) =4259571a(11) =69302975a(12) =136410197a(13) =200533921a(14) =313742585a(15) =603439225a(16) =1516358753a(17) =2563893625a(18) =3326174929a(19) =5655792025a(20) =10214476341a(21) =25937424601a(22) =29677977573a(23) =59797108943a(24) =283867750439a(25) =715167055525