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

A066939

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

Terms

    a(0) =13954a(1) =106899a(2) =307835a(3) =783201a(4) =979731a(5) =2980255a(6) =9266817a(7) =18479215a(8) =49062925a(9) =109044425a(10) =114029313a(11) =120914101a(12) =185480686a(13) =218223299a(14) =347941741a(15) =429365395a(16) =466423743a(17) =492508289a(18) =610803875a(19) =895938847a(20) =993189741a(21) =1093958383

External references