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A285385 Positions of 1 in A285384; complement of A072939.

%I A285385 #14 Jan 29 2025 18:21:45
%S A285385 1,2,4,5,6,8,10,12,13,14,16,17,18,20,21,22,24,26,28,29,30,32,34,36,37,
%T A285385 38,40,42,44,45,46,48,49,50,52,53,54,56,58,60,61,62,64,65,66,68,69,70,
%U A285385 72,74,76,77,78,80,81,82,84,85,86,88,90,92,93,94,96,98
%N A285385 Positions of 1 in A285384; complement of A072939.
%H A285385 Clark Kimberling, <a href="/A285385/b285385.txt">Table of n, a(n) for n = 1..10000</a>
%F A285385 a(n) = A171946(n) for n>=2.
%F A285385 a(n + 1) = a(n) + A096268(a(n) - 1) + 1 for all n > 0. (conjecture) - _Velin Yanev_, Mar 23 2019
%e A285385 As a word, A285384 = 11011101..., in which the positions of 1 are 1,2,4,5,6,8,...
%t A285385 s = Nest[Flatten[# /. {0 -> {1, 1}, 1 -> {0, 1}}] &, {0}, 16] (* A285384 *)
%t A285385 Flatten[Position[s, 0]]  (* A072939 *)
%t A285385 Flatten[Position[s, 1]]  (* A285385 *)
%o A285385 (Python)
%o A285385 def A285385(n):
%o A285385     def f(x):
%o A285385         c, s = n, bin(x-1)[2:]
%o A285385         l = len(s)
%o A285385         for i in range(l&1,l,2):
%o A285385             c += int(s[i])+int('0'+s[:i],2)
%o A285385         return c
%o A285385     m, k = n, f(n)
%o A285385     while m != k: m, k = k, f(k)
%o A285385     return m # _Chai Wah Wu_, Jan 29 2025
%Y A285385 Cf. A072939, A171946, A285384.
%K A285385 nonn,easy
%O A285385 1,2
%A A285385 _Clark Kimberling_, Apr 26 2017