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A285968 Positions of 1 in A285966; complement of A285967. 3

%I #9 Mar 23 2019 05:35:44

%S 2,4,7,10,12,14,17,19,22,24,27,30,32,35,37,40,42,44,47,50,52,54,57,59,

%T 62,64,67,69,71,74,77,79,82,84,87,90,92,94,97,99,102,104,107,110,112,

%U 115,117,120,122,124,127,130,132,135,137,140,143,145,147,150

%N Positions of 1 in A285966; complement of A285967.

%C Conjecture: a(n)/n -> 5/2.

%C From _Michel Dekking_, Mar 15 2019: (Start)

%C Proof of this conjecture: it is equivalent to prove that the frequency of 1 in A285966 exists and equals 2/5.

%C This follows from my characterization of A285966 as a morphic sequence.

%C The incidence matrix of that morphism has Perron-Frobenius eigenvalue 2, with right eigenvector (1,1,2,1). It follows that the letters 2 and 4 in the fixed point of the morphism have both frequency 1/5. As these are exactly the letters that are mapped to 1 in A285966, the letter 1 has frequency 2/5 in A285966.

%C (End)

%H Clark Kimberling, <a href="/A285968/b285968.txt">Table of n, a(n) for n = 1..10000</a>

%e As a word, A285966 = 01010010010101001010010..., in which 1 is in positions 2,4,7,10,12,...

%t s = Nest[Flatten[# /. {0 -> {0, 1}, 1 -> {1, 0}}] &, {0}, 9] (* Thue-Morse, A010060 *)

%t w = StringJoin[Map[ToString, s]]

%t w1 = StringReplace[w, {"11" -> "1"}]

%t st = ToCharacterCode[w1] - 48 (* A285966 *)

%t Flatten[Position[st, 0]] (* A285967 *)

%t Flatten[Position[st, 1]] (* A285968 *)

%Y Cf. A010060, A285966, A285967.

%K nonn,easy

%O 1,1

%A _Clark Kimberling_, May 06 2017

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Last modified April 24 20:08 EDT 2024. Contains 371963 sequences. (Running on oeis4.)