Numbers k for which phi(k) = phi(k''), where phi is the Euler totient function (A000010) and k'' the second arithmetic derivative of k (A068346).

A352331

Numbers k for which phi(k) = phi(k''), where phi is the Euler totient function (A000010) and k'' the second arithmetic derivative of k (A068346).

Terms

    a(0) =4a(1) =27a(2) =104a(3) =260a(4) =296a(5) =405a(6) =525a(7) =740a(8) =910a(9) =945a(10) =1460a(11) =1806a(12) =1818a(13) =2504a(14) =3125a(15) =3140a(16) =3176a(17) =3656a(18) =3860a(19) =4563a(20) =5540a(21) =6056a(22) =6930a(23) =7016a(24) =8420a(25) =8636a(26) =9224a(27) =10820a(28) =12573a(29) =13256

External references