This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A322407 #18 Oct 14 2019 00:26:34
%S A322407 0,1,3,4,4,5,7,8,9,11,12,12,13,15,16,18,19,19,20,22,23,24,26,27,27,28,
%T A322407 30,31,31,32,34,35,36,38,39,39,40,42,43,45,46,46,47,49,50,51,53,54,54,
%U A322407 55,57,58,59,61,62,62,63,65,66,68,69
%N A322407 Compound sequence a(n) = A319198(A278039(n)), for n >= 0.
%C A322407 Old name was: Compound tribonacci sequence a(n) = A319198(A278039(n)), for n >= 0.
%C A322407 a(n) gives the sum of the entries of the tribonacci word sequence t = A080843 not exceeding t(B(n)), with B(n) = A278039(n).
%F A322407 a(n) = z(B(n)) = Sum_{j=0..B(n)} t(j), n >= 0, with z = A319198, B = A278039 and t = A080843.
%F A322407 a(n) = -A(n) + 3*B(n) - (n - 1), where A(n) = A278040(n). For a proof see the W. Lang link in A080843, Proposition 8, eq. (46).
%F A322407 a(n) = Sum_{k=1..n-1} d(k), where d is the tribonacci sequence on the alphabet {1,2,0}. - _Michel Dekking_, Oct 08 2019
%e A322407 n = 3: B(3) = 6, t = {0, 1, 0, 2, 0, 1, 0, ...} which sums to 4 = a(3) = -12 + 3*6 - 2, because A(3) = 12.
%Y A322407 Cf. A080843, A278040, A278039, A319198, A321333, A322408.
%K A322407 nonn,easy
%O A322407 0,3
%A A322407 _Wolfdieter Lang_, Jan 02 2019
%E A322407 Name changed by _Michel Dekking_, Oct 07 2019