Numbers k such that phi(k) - k = phi(k') - k', where k' is the arithmetic derivative of k and phi(k) is the Euler totient function.

A239940

Numbers k such that phi(k) - k = phi(k') - k', where k' is the arithmetic derivative of k and phi(k) is the Euler totient function.

Terms

    a(0) =1a(1) =4a(2) =12a(3) =27a(4) =28a(5) =124a(6) =279a(7) =508a(8) =1175a(9) =3125a(10) =7767a(11) =18125a(12) =32764a(13) =38205a(14) =53757a(15) =68013a(16) =86999a(17) =153575a(18) =171549a(19) =171875a(20) =271875a(21) =496341a(22) =524284a(23) =823543a(24) =1160541a(25) =1344573a(26) =1900557a(27) =1945233a(28) =2097148a(29) =2828375

External references