A319695 Number of distinct values obtained when Euler phi (A000010) is applied to proper divisors of n.

0, 1, 1, 1, 1, 2, 1, 2, 2, 2, 1, 2, 1, 2, 3, 3, 1, 3, 1, 3, 3, 2, 1, 3, 2, 2, 3, 3, 1, 4, 1, 4, 3, 2, 3, 4, 1, 2, 3, 4, 1, 4, 1, 3, 5, 2, 1, 4, 2, 3, 3, 3, 1, 4, 3, 5, 3, 2, 1, 4, 1, 2, 4, 5, 3, 4, 1, 3, 3, 4, 1, 6, 1, 2, 5, 3, 3, 4, 1, 5, 4, 2, 1, 5, 3, 2, 3, 5, 1, 6, 3, 3, 3, 2, 3, 5, 1, 3, 5, 5, 1, 4, 1, 5, 7

Offset: 1

Author

Antti Karttunen, Oct 02 2018

Keywords

• nonn

Examples

			For n = 6, it has three proper divisors: 1, 2, 3, and applying A000010 to these gives 1, 1 and 2, with just two distinct values, thus a(6) = 2.
		

Links

• Antti Karttunen, Table of n, a(n) for n = 1..65537

Crossrefs

Cf. A000010, A319696.

Cf. also A304793, A305611, A316555, A316556, A319685 for similarly constructed sequences.

Programs

PARI

A319695(n) = { my(m=Map(),s,k=0); fordiv(n,d,if((d