login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A226631
Length of the shortest primitive cycle(s) of positive integers under iteration by the 3x-k function, where k=A226630(n).
3
1, 4, 6, 17, 19, 34, 12, 9, 5, 22, 12, 17, 17, 69, 7, 18, 22, 38, 11, 12, 6, 68, 44, 30, 9, 19, 68, 14, 22, 44, 23, 30, 84, 8, 17, 17, 30, 12, 68, 18, 7, 22, 15, 22, 85, 10, 14, 22, 22, 10, 14, 18, 44, 12, 68, 22, 9, 38, 17, 14, 55, 8, 56, 50, 36, 44, 25, 37
OFFSET
1,2
COMMENTS
A cycle is called primitive if its elements are not a common multiple of the elements of another cycle.
The 3x-k function T_k is defined by T_k(x) = x/2 if x is even, (3x-k)/2 if x is odd.
LINKS
FORMULA
a(n) = min_{j=A226628(n) to A226628(n+1)-1} A226625(j).
CROSSREFS
Sequence in context: A190968 A127416 A306017 * A226634 A105271 A343758
KEYWORD
nonn
AUTHOR
Geoffrey H. Morley, Jun 14 2013
STATUS
approved