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A107792
Threes order in the tribonacci substitution of three symbols.
0
3, 5, 8, 9, 12, 14, 17, 19, 22, 23, 26, 28, 31, 34, 36, 39, 40, 43, 45, 48, 49, 52, 54, 57, 60, 62, 65, 66, 69, 71, 74, 76, 79, 80, 83, 85, 88, 91, 93, 96, 97, 100, 102, 105, 107, 110, 111, 114, 116, 119, 122, 124, 127, 128, 131, 133, 136, 137, 140, 142, 145, 148, 150
OFFSET
0,1
FORMULA
1->(2), 2->{3}, 3->{1, 2, 3}, a(n) = order of appearance of threes in the substitution
MATHEMATICA
s[1] = {2}; s[2] = {3};; s[3] = {1, 2, 3}; t[a_] := Flatten[s /@ a]; p[0] = {1}; p[1] = t[p[0]]; p[n_] := t[p[n - 1]] pp = p[12] a = Flatten[Table[If[pp[[j]] == 3, j, {}], {j, 1, Length[pp]}]]
CROSSREFS
Sequence in context: A325168 A211703 A274430 * A051206 A081451 A107605
KEYWORD
nonn,uned
AUTHOR
Roger L. Bagula, Jun 11 2005
STATUS
approved