a(n) = gcd(d(n), phi(n)), where d is the number of divisors of n (A000005) and phi is Euler's totient function (A000010).

A009213

a(n) = gcd(d(n), phi(n)), where d is the number of divisors of n (A000005) and phi is Euler's totient function (A000010).

Terms

    a(0) =1a(1) =1a(2) =2a(3) =1a(4) =2a(5) =2a(6) =2a(7) =4a(8) =3a(9) =4a(10) =2a(11) =2a(12) =2a(13) =2a(14) =4a(15) =1a(16) =2a(17) =6a(18) =2a(19) =2a(20) =4a(21) =2a(22) =2a(23) =8a(24) =1a(25) =4a(26) =2a(27) =6a(28) =2a(29) =8

External references