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 A317206 #30 Jan 16 2019 04:12:44 %S A317206 0,1,2,12,3,112,22,13,1112,212,122,32,113,23,11112,2112,1212,312,1122, %T A317206 222,132,1113,213,123,33,111112,21112,12112,3112,11212,2212,1312, %U A317206 11122,2122,1222,322,1132,232,11113,2113,1213,313,1123,223,133,1111112,211112 %N A317206 An alternative tribonacci representation of n: an encoding of the position of n in the A003144, A003145, A003146 table. %C A317206 Let T denote the following 4-rowed table, whose rows are n, A = A003144(n), B = A003145(n), C = A003146(n): %C A317206 n: 1 .2 .3 .4 .5 .6 .7 .8 .9 ... %C A317206 A: 1 .3 .5 .7 .8 10 ... %C A317206 B: 2 .6 .9 13 15 19 ... %C A317206 C: 4 11 17 24 28 35 ... %C A317206 Set a(0)=0. For n>0, locate n in rows A, B, C of the table, and indicate how to reach that entry starting from column 1. For example, 17 = C(3) = C(A(2)) = C(A(B(1))), so the path to reach 17 is CAB, which we write (encoding A as 1, B as 2, C as 3) as a(17) = 312. %C A317206 This is an analog of the Wythoff representation of n described in Lang (1996), A189921, and A317208. %D A317206 W. Lang, The Wythoff and the Zeckendorf representations of numbers are equivalent, in G. E. Bergum et al. (edts.) Application of Fibonacci numbers vol. 6, Kluwer, Dordrecht, 1996, pp. 319-337. [See A317208 for a link.] %H A317206 Lars Blomberg, <a href="/A317206/b317206.txt">Table of n, a(n) for n = 0..10000</a> %H A317206 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. %Y A317206 See A278038 for the standard tribonacci representation of n. %Y A317206 See A189921 and A317208 for the analogous Wythoff representation of n. %Y A317206 Cf. A317207. %K A317206 nonn,base %O A317206 0,3 %A A317206 _N. J. A. Sloane_, Aug 09 2018 %E A317206 Inserted a(10) and a(18) and beyond from _Lars Blomberg_, Aug 11 2018