A276040 Least k such that n^n divides phi(k^k) (k > 0).

1, 4, 6, 8, 10, 12, 14, 12, 18, 20, 22, 24, 26, 28, 30, 24, 34, 36, 38, 40, 42, 44, 46, 36, 50, 52, 45, 56, 58, 60, 62, 48, 66, 68, 70, 72, 74, 76, 78, 60, 82, 84, 86, 88, 90, 92, 94, 72, 98, 100, 102, 104, 106, 90, 110, 84, 114, 116, 118, 120

Offset

1,2

Comments

Indices of odd terms in this sequence are 1, 27, 81, 135, 189, 297, 343, 351, 405, 459, 513, 621, 625, 675, 783, ...

Links

Table of n, a(n) for n=1..60.

Example

a(3) = 6 because 3^3 divides phi(6^6) = 15552.

Mathematica

Table[k = 1; While[! Divisible[EulerPhi[k^k], n^n], k++]; k, {n, 60}] (* Michael De Vlieger, Aug 21 2016 *)

Prog

(PARI) a(n) = {my(k = 1); while(eulerphi(k^k) % n^n, k++); k; }

Crossrefs

Cf. A064447.

Sequence in context: A063287 A228358 A134331 * A360694 A090334 A272601

Adjacent sequences: A276037 A276038 A276039 * A276041 A276042 A276043

Keyword

nonn

Author

Altug Alkan, Aug 17 2016

Status

approved