%I #15 Mar 07 2020 13:50:20
%S 7,6,7,4,7,6,7,7,6,7,4,7,6,7,6,7,4,7,6,7,7,6,7,4,7,6,7,4,7,6,7,7,6,7,
%T 4,7,6,7,6,7,4,7,6,7,7,6,7,4,7,6,7,7,6,7,4,7,6,7,6,7,4,7,6,7,7,6,7,4,
%U 7,6,7,4,7,6,7,7,6,7,4,7,6,7,6,7,4,7,6,7,7,6,7,4,7,6,7,6,7,4,7
%N First differences of A003146.
%H Rémy Sigrist, <a href="/A276792/b276792.txt">Table of n, a(n) for n = 1..10608</a>
%H Elena Barcucci, Luc Belanger and Srecko Brlek, <a href="http://www.fq.math.ca/Papers1/42-4/quartbarcucci04_2004.pdf">On tribonacci sequences</a>, Fib. Q., 42 (2004), 314-320. See page 317.
%H F. Michel Dekking, Jeffrey Shallit, and N. J. A. Sloane, <a href="https://www.combinatorics.org/ojs/index.php/eljc/article/view/v27i1p52/8039">Queens in exile: non-attacking queens on infinite chess boards</a>, Electronic J. Combin., 27:1 (2020), #P1.52.
%F a(n) = A003146(n+1) - A003146(n), for n >= 1.
%F a(n) = A276788(n) + A276789(n) + 1, for n >= 1.
%F a(n+1) = 7 - t(n)*(t(n) + 1)/2, n >= 0, where t(n) = A080843(n). - _Wolfdieter Lang_, Dec 06 2018
%Y Cf. A003144, A003145, A003146, A080843, A276788, A276789.
%K nonn,easy
%O 1,1
%A _N. J. A. Sloane_, Oct 27 2016