A107604 - OEIS

%I #3 Mar 30 2012 17:34:15

%S 2,2,2,2,5,2,5,2,5,7,2,5,7,2,5,7,2,5,7,10,2,5,7,10,2,5,7,10,2,5,7,10,

%T 13,2,5,7,10,13,2,5,7,10,13,15,2,5,7,10,13,15,2,5,7,10,13,15,2,5,7,10,

%U 13,15,18,2,5,7,10,13,15,18,2,5,7,10,13,15,18,20

%N Order of appearance of twos in the Fibonacci substitution :triangular in form.

%C Fibonacci substitutions contain thrre types of informstion: 1) length 2) count of ones and twos 3) order of appearance of ones and twos

%F 1->{1, 2}, 2->{1}

%e {}

%e 2,

%e 2,

%e 2,

%e 2,5,

%e 2,5,

%e 2,5,7,

%e 2,5,7,

%e 2,5,7,

%e 2,5,7,10,

%e 2,5,7,10,

%e 2,5,7,10,

%e 2,5,7,10,13

%t s[1] = {1, 2}; s[2] = {1};; t[a_] := Flatten[s /@ a]; p[0] = {1}; p[1] = t[p[0]]; p[n_] := t[p[n - 1]] a = Table[Flatten[Table[If[p[i][[j]] == 2, j, {}], {j, 1, i}]], {i, 1, 20}]

%Y Cf. A000045.

%K nonn,uned,tabl

%O 0,1

%A _Roger L. Bagula_, Jun 09 2005