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 A343604 #10 Apr 25 2021 15:13:45
%S A343604 2,3,6,7,10,15,8,9,16,11,12,19,22,31,42,17,18,23,20,21,24,25,28,43,26,
%T A343604 27,32,29,30,33,34,37,46,35,36,49,38,39,58,67,94,123,44,45,50,47,48,
%U A343604 51,52,55,68,53,54,59,56,57,60,61,64,69,62,63,70,65,66,73
%N A343604 a(n) is the least number > n with the same sum of balanced ternary digits as n.
%C A343604 This sequence can be extended to negative indexes by setting a(-n) = -A343605(n) for any n > 0.
%H A343604 Rémy Sigrist, <a href="/A343604/b343604.txt">Table of n, a(n) for n = 0..10000</a>
%F A343604 a(9*n) = 9*n + 2.
%F A343604 a(A174658(n)) = A174658(n+1).
%e A343604 The first terms, in base 10 and in balanced ternary (where T denotes the digit -1), alongside A065363(n), are:
%e A343604 n a(n) bter(n) bter(a(n)) A065363(n)
%e A343604 -- ---- ------- ---------- ----------
%e A343604 0 2 0 1T 0
%e A343604 1 3 1 10 1
%e A343604 2 6 1T 1T0 0
%e A343604 3 7 10 1T1 1
%e A343604 4 10 11 101 2
%e A343604 5 15 1TT 1TT0 -1
%e A343604 6 8 1T0 10T 0
%e A343604 7 9 1T1 100 1
%e A343604 8 16 10T 1TT1 0
%e A343604 9 11 100 11T 1
%e A343604 10 12 101 110 2
%e A343604 11 19 11T 1T01 1
%e A343604 12 22 110 1T11 2
%o A343604 (PARI) A065363(n) = { my (v=0, d); while (n, v+=d=centerlift(Mod(n,3)); n=(n-d)\3); v }
%o A343604 a(n) = my (s=A065363(n)); for (k=n+1, oo, if (s==A065363(k), return (k)))
%Y A343604 Cf. A057168, A065363, A174658, A228915, A319021, A343605.
%K A343604 nonn,base
%O A343604 0,1
%A A343604 _Rémy Sigrist_, Apr 22 2021