Numbers k such that sigma(phi(k)) - phi(k) = phi(sigma(k)), where phi(k) is the Euler totient function of k and sigma(k) is the sum of the divisors of k.
A271633
Numbers k such that sigma(phi(k)) - phi(k) = phi(sigma(k)), where phi(k) is the Euler totient function of k and sigma(k) is the sum of the divisors of k.
Terms
- a(0) =21a(1) =350a(2) =366a(3) =532a(4) =702a(5) =1072a(6) =5264a(7) =7128a(8) =23604a(9) =24102a(10) =30222a(11) =30636a(12) =32142a(13) =32274a(14) =34350a(15) =47338a(16) =70722a(17) =78530a(18) =113550a(19) =137214a(20) =197316a(21) =235624a(22) =292206a(23) =357490a(24) =367704a(25) =398346a(26) =406596a(27) =453096a(28) =453264a(29) =464820
External references
- oeis: A271633