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 A038106 #18 Mar 11 2023 12:34:35
%S A038106 0,1,2,3,4,5,45240,45241,45242,45243,45244,45245,54000,54001,54002,
%T A038106 54003,54004,54005,304200,304201,304202,304203,304204,304205,3240000,
%U A038106 3240001,3240002,3240003,3240004,3240005,3544200,3544201,3544202
%N A038106 Numbers k with the property that k is a substring of its base-6 representation.
%H A038106 Giovanni Resta, <a href="/A038106/b038106.txt">Table of n, a(n) for n = 1..125</a> (terms < 10^18)
%e A038106 304201_10 = 10{304201}_6.
%t A038106 Select[Range[0,355*10^4],SequenceCount[IntegerDigits[#,6],IntegerDigits[#]]>0&] (* _Harvey P. Dale_, Mar 11 2023 *)
%Y A038106 Cf. A038102-A038105, A228050-A228052, A227549.
%K A038106 nonn,base
%O A038106 1,3
%A A038106 _Patrick De Geest_, Feb 15 1999