Numbers n such that sigma (phi ( n ) ) = sigma (sigma (n ) ) where phi is Euler's totient and sigma is the multiplicative sum-of-divisors function.

A065556

Numbers n such that sigma (phi ( n ) ) = sigma (sigma (n ) ) where phi is Euler's totient and sigma is the multiplicative sum-of-divisors function.

Terms

    a(0) =1a(1) =367a(2) =919a(3) =1967a(4) =3641a(5) =4379a(6) =5143a(7) =7379a(8) =11843a(9) =12767a(10) =13493a(11) =15293a(12) =21797a(13) =26039a(14) =28381a(15) =29807a(16) =30263a(17) =30593a(18) =30599a(19) =30887a(20) =37523a(21) =40199a(22) =48559a(23) =49781a(24) =51101a(25) =51397a(26) =55277a(27) =62573a(28) =67223a(29) =72433

External references