a(n) is the smallest number k such that psi(k) = n*phi(k) where psi(k) is Dedekind psi function (A001615) and phi(k) is Euler totient function (A000010), or 0 if no such k exists.

A291051

a(n) is the smallest number k such that psi(k) = n*phi(k) where psi(k) is Dedekind psi function (A001615) and phi(k) is Euler totient function (A000010), or 0 if no such k exists.

Terms

    a(0) =1a(1) =3a(2) =2a(3) =14a(4) =190a(5) =6a(6) =78a(7) =42a(8) =30a(9) =570a(10) =16770a(11) =210a(12) =1102290a(13) =2730a(14) =67830a(15) =43890a(16) =133707210a(17) =746130a(18) =27606810a(19) =16546530a(20) =9699690a(21) =417086670a(23) =8720021310a(24) =705196562070

External references