

A309363


Van Eck's sequence (cf. A181391), but outputting 2 for a new number, not 0.


2



0, 2, 2, 1, 2, 2, 1, 3, 2, 3, 2, 2, 1, 6, 2, 3, 6, 3, 2, 4, 2, 2, 1, 10, 2, 3, 8, 2, 3, 3, 1, 8, 5, 2, 6, 18, 2, 3, 8, 7, 2, 4, 22, 2, 3, 7, 6, 12, 2, 5, 17, 2, 3, 8, 15, 2, 4, 15, 3, 6, 13, 2, 6, 3, 5, 15, 8, 13, 7, 23, 2, 9, 2, 2, 1, 44
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,2


COMMENTS

After the initial value, the sequence is extended by a(n+1) = min { k > 0: a(nk) = a(n) } or 2 if no such k exists, i.e., if a(n) did not appear earlier.
Although the sequence has properties that are superficially similar to the original A181391, there is an important difference. Using a positive number m instead of 0 to mark a new value means there is no 1to1 correspondence between the occurrence of a new value and the occurrence of m.  Jan Ritsema van Eck, Aug 14 2019


LINKS

Rémy Sigrist, Table of n, a(n) for n = 1..25000


CROSSREFS

Cf. A181391, A171911, ..., A171918 (same but starting with 0, 1, 2, ..., 8 and returning 0 when a new term appears).
Sequence in context: A227156 A123369 A178306 * A280153 A023671 A302243
Adjacent sequences: A309360 A309361 A309362 * A309364 A309365 A309366


KEYWORD

nonn


AUTHOR

Nicholas FitzGerald, Jul 25 2019


STATUS

approved



