A078711 Sequence is S(infinity), where S(1)={1,2,3}, S(n+1)=S(n)S'(n) and S'(n) is obtained from S(n) by changing last term using the cyclic permutation 1->2->3->1.

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

Offset

1,2

Links

Paolo Xausa, Table of n, a(n) for n = 1..12288

Formula

Lim_{n->infinity} Sum_{i=1..n} a(i)/n = 37/21; density of 1's is 3/7; density of 2's is 8/21; density of 3's is 4/21.

Example

Concatenating 1,2,3 gives 1,2,3,1,2,3; changing the last term 3 to 1 gives the first 6 terms: 1,2,3,1,2,1. Concatenating those 6 terms: 1,2,3,1,2,1,1,2,3,1,2,1; replacing the last term 1 with 3 gives the first 12 terms: 1,2,3,1,2,1,1,2,3,1,2,2.

Mathematica

A078711list[i_]:=Nest[Join[#, Most[#], {Mod[Last[#], 3]+1}]&, Range[3], i];
A078711list[6] (* Each iteration doubles the number of terms *) (* Paolo Xausa, Aug 31 2023 *)

Crossrefs

Cf. A010060, A078978, A078979.

Sequence in context: A091654 A127246 A106038 * A338850 A322423 A325494

Adjacent sequences: A078708 A078709 A078710 * A078712 A078713 A078714

Keyword

nonn

Author

Benoit Cloitre, Dec 19 2002

Status

approved