A276791 Indicator function of (A003146 prefixed with 0).

1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0

Offset

0

Comments

Also, this has 1's where A275925 has 3's (which is why the offset is 0).

Also, apart from the initial 1, this has 1's where the tribonacci word A080843 has 2's.

a(n+1) = 1 iff n is a member of A278041, for n >= 0. - Wolfdieter Lang, Dec 06 2018

Links

N. J. A. Sloane, Table of n, a(n) for n = 0..10000

Wolfdieter Lang, The Tribonacci and ABC Representations of Numbers are Equivalent, arXiv preprint arXiv:1810.09787 [math.NT], 2018.

Formula

a(n+1) = t(n)*(t(n) - 1)/2, for n >= 0, and a(0) = 0, where t(n) = A080843(n). - Wolfdieter Lang, Dec 06 2018

Crossrefs

Cf. A003146, A080843, A275925, A278041.

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

Sequence in context: A016049 A015569 A015329 * A111900 A173860 A123192

Adjacent sequences: A276788 A276789 A276790 * A276792 A276793 A276794

Keyword

nonn,easy

Author

N. J. A. Sloane, Oct 18 2016

Extensions

More precise definition by Georg Fischer, Sep 01 2020

Status

approved