OFFSET
1,3
COMMENTS
(a(n)) is a morphic sequence, i.e., a letter-to-letter projection of a fixed point of a morphism. See A026608 and A026610. - Michel Dekking, Apr 16 2019
The frequencies of 0's, 1's and 2's in (a(n)) are 4/13, 5/13 and 4/13. See A026610. - Michel Dekking, Apr 16 2019
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..19682
MATHEMATICA
Rest@ Map[Count[#, 2] &, DeleteCases[SplitBy[#, # == 3 &], _?(# == {3} &)]] &@ Nest[Flatten[# /. {1 -> {1, 2, 3}, 2 -> {2, 3, 1}, 3 -> {3, 1, 2}}] &, {1}, 6] (* Michael De Vlieger, Apr 16 2019, after Robert G. Wilson v at A026600 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved