A241665 Number of iterations of A241663 needed to reach either 0 or 1.

1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 3, 1, 2, 1, 1, 1, 3, 1, 2, 1, 1, 1, 3, 1, 2, 1, 1, 1, 3, 1, 2, 1, 1, 1, 2, 1, 2, 1, 1, 1, 3, 1, 2, 1, 1, 1, 3, 1, 2, 1, 1, 1, 3, 1, 3, 1, 1, 1, 4, 1, 2, 1, 1, 1, 2, 1, 2, 1, 1, 1, 3, 1, 2, 1, 1, 1, 2, 1, 2, 1, 1, 1, 3, 1, 3, 1, 1, 1, 4, 1, 2, 1, 1, 1, 2, 1, 2, 1, 1, 1, 3, 1, 2, 1, 1

Offset: 1

Author

Colin Defant, Apr 26 2014

Keywords

• nonn

Comments

It might be more natural to define the initial terms as a(0) = a(1) = 0 for the sake of recurrence. - Antti Karttunen, Oct 01 2018

Examples

			A241663(11)=7, A241663(7)=3, A241663(3)=0. Thus, a(11)=3.
		

Links

• Antti Karttunen, Table of n, a(n) for n = 1..65537
• C. Defant, On Arithmetic Functions Related to Iterates of the Schemmel Totient Functions, J. Int. Seq. 18 (2015) # 15.2.1
• Colin Defant, Python program

Crossrefs

Cf. A241663, A241668.

Programs

PARI

A241663(n) = {my(f = factor(n)); prod(i=1, #f~, if ((f[i, 1] == 2) || (f[i, 1] == 3), 0, f[i, 1]^(f[i, 2]-1)*(f[i, 1]-4))); } \\ From A241663
A241665(n) = { my(s=(1==n)); while(n>1, n = A241663(n); s++); (s); }; \\ Antti Karttunen, Oct 01 2018

Python

# See Defant link. Enter m=4, as well as starting and ending values of n. The third string of numbers will be this sequence.

Extensions

More terms from Alois P. Heinz, Apr 30 2014

Terms a(88) .. a(105) from Antti Karttunen, Oct 01 2018