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 A033068 #18 Apr 07 2022 06:28:12
%S A033068 1,2,3,5,7,10,16,21,23,30,32,48,50,64,70,91,97,145,151,192,194,210,
%T A033068 212,273,275,291,293,435,437,453,455,577,583,631,637,820,826,874,880,
%U A033068 1306,1312,1360,1366,1731,1733,1749,1751,1893,1895,1911,1913,2460,2462,2478
%N A033068 Numbers with the property that all pairs of consecutive base-3 digits differ by 1.
%H A033068 Amiram Eldar, <a href="/A033068/b033068.txt">Table of n, a(n) for n = 1..10000</a>
%t A033068 Join[Range[2],Select[Range[2000],Union[Abs[Differences[IntegerDigits[#,3]]]]=={1}&]] (* _Harvey P. Dale_, Dec 28 2011 *)
%Y A033068 Cf. A007089.
%K A033068 nonn,base
%O A033068 1,2
%A A033068 _Clark Kimberling_