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 A060583 #20 Feb 03 2021 23:04:42
%S A060583 0,2,1,7,6,8,5,4,3,23,22,21,18,20,19,25,24,26,16,15,17,14,13,12,9,11,
%T A060583 10,70,69,71,68,67,66,63,65,64,54,56,55,61,60,62,59,58,57,77,76,75,72,
%U A060583 74,73,79,78,80,50,49,48,45,47,46,52,51,53,43,42,44,41,40,39,36,38,37
%N A060583 A ternary code related to the Tower of Hanoi.
%C A060583 Write n in base 3, then (working from left to right) if the k-th digit of n is equal to the corresponding digit to the left of the k-th digit of a(n) then this is the k-th digit of a(n), otherwise the k-th digit of a(n) is the element of {0,1,2} which has not just been compared, then read result as a base 3 number.
%H A060583 Alois P. Heinz, <a href="/A060583/b060583.txt">Table of n, a(n) for n = 0..6560</a>
%H A060583 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>
%F A060583 a(n) = 3*a(floor(n/3)) + ((-a(floor(n/3))-n) mod 3) = 3*a(floor(n/3)) + A060582(n) with a(0)=0.
%e A060583 a(46) = 76 since 43 = 1201_3; this gives a first digit of 2(=3-1-0), a second digit of 2(=2=2), a third digit of 1(=3-2-0) and a fourth digit of 1(=1=1); 2211_3 = 76.
%Y A060583 Cf. A060586, A060587 (inverse).
%K A060583 base,nonn,look
%O A060583 0,2
%A A060583 _Henry Bottomley_, Apr 04 2001