Numbers k for which phi(k)+1 is a multiple of d(k), where phi is Euler totient function (A000010) and d(n) gives the number of divisors of n (A000005).
A342665
Numbers k for which phi(k)+1 is a multiple of d(k), where phi is Euler totient function (A000010) and d(n) gives the number of divisors of n (A000005).
Terms
- a(0) =1a(1) =2a(2) =4a(3) =25a(4) =81a(5) =121a(6) =289a(7) =529a(8) =841a(9) =1681a(10) =2209a(11) =2809a(12) =3481a(13) =5041a(14) =6889a(15) =7921a(16) =10201a(17) =11449a(18) =12100a(19) =12769a(20) =17161a(21) =18769a(22) =22201a(23) =27889a(24) =28561a(25) =28900a(26) =29929a(27) =32041a(28) =36481a(29) =38809
External references
- oeis: A342665