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Indicator function for A003145.
7

%I #24 Jan 16 2019 11:53:44

%S 0,0,1,0,0,0,1,0,0,1,0,0,0,1,0,1,0,0,0,1,0,0,1,0,0,0,1,0,0,0,1,0,0,1,

%T 0,0,0,1,0,1,0,0,0,1,0,0,1,0,0,0,1,0,0,1,0,0,0,1,0,1,0,0,0,1,0,0,1,0,

%U 0,0,1,0,0,0,1,0,0,1,0,0,0,1,0,1,0,0,0,1,0,0,1,0,0,0,1,0,1,0,0,0

%N Indicator function for A003145.

%C a(n) = 1 iff n is a member of A003145.

%C a(n+1) = 1 iff n is a member of A278040, for n >= 0. - _Wolfdieter Lang_, Dec 06 2018

%H N. J. A. Sloane, <a href="/A276794/b276794.txt">Table of n, a(n) for n = 0..10000</a>

%H Wolfdieter Lang, <a href="https://arxiv.org/abs/1810.09787">The Tribonacci and ABC Representations of Numbers are Equivalent</a>, arXiv preprint arXiv:1810.09787 [math.NT], 2018.

%H <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>

%F a(n+1) = t(n)*(2 - t(n)), where t(n) = A080843(n), for n >= 0; and a(0) = 0. - _Wolfdieter Lang_, Dec 06 2018

%Y Cf. A003145, A080843, A276797, A278040.

%Y A276793(n)+A276794(n)+A276791(n)=1; A276796(n)+A276797(n)+A276798(n)=n+1.

%K nonn,easy

%O 0

%A _N. J. A. Sloane_, Oct 28 2016