A395960 - OEIS

%I #11 May 19 2026 19:42:09

%S 1,2,5,6,9,10,13,14,16,19,20,23,24,27,28,31,32,35,36,39,40,43,44,47,

%T 49,50,53,54,57,58,61,62,65,66,69,70,73,74,77,78,80,83,84,87,88,91,92,

%U 95,96,99,100,103,104,107,108,111,113,114,117,118

%N Numbers k such that A395958(k) = 1.

%C Complement of A395959.

%H Benoit Cloitre, <a href="https://arxiv.org/abs/2604.06243">The Thue-Morse Transform</a>, arXiv:2604.06243 [math.NT], 2026.

%F a(n) = 2*(n-1) + 1 - A395958(2*(n-1)) for n >= 1.

%o (Python)

%o def A395958(n):

%o     s, p = 0, 0

%o     while (1 << p) <= n:

%o         if (p & 2) == 0:

%o             s ^= (n >> p) & 1

%o         p += 1

%o     return s

%o print([k for k in range(120) if A395958(k) == 1])

%Y Cf. A000035, A000069, A001969, A010060, A158704, A158705, A341389, A395958, A395959, A395961, A395962, A395963, A395964, A395965, A395966.

%K nonn,base,easy

%O 1,2

%A _Benoit Cloitre_, May 12 2026