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 A037388 #17 Aug 04 2021 02:21:41 %S A037388 1,2,3,15,38,55,63,73,85,91,117,119,121,127,170,231,236,243,255,256, %T A037388 257,264,276,288,289,290,291,292,293,294,306,324,325,326,327,336,341, %U A037388 343,348,349,350,351,362,375,381,383,408,409,410 %N A037388 Numbers k such that every base-4 digit of k is a base-6 digit of k. %H A037388 Reinhard Zumkeller, <a href="/A037388/b037388.txt">Table of n, a(n) for n = 1..10000</a> %t A037388 Select[Range[500],SubsetQ[IntegerDigits[#,6],IntegerDigits[#,4]]&] (* _Harvey P. Dale_, Mar 19 2018 *) %o A037388 (Haskell) %o A037388 import Data.List ((\\), nub) %o A037388 a037388 n = a037388_list !! (n-1) %o A037388 a037388_list = filter f [1..] where %o A037388 f x = null $ nub (ds 4 x) \\ nub (ds 6 x) %o A037388 ds b x = if x > 0 then d : ds b x' else [] where (x', d) = divMod x b %o A037388 -- _Reinhard Zumkeller_, May 30 2013 %Y A037388 Cf. A007090, A007092. %Y A037388 Cf. A037387, A037389, A037390, A037391, A037392. %K A037388 nonn,base %O A037388 1,2 %A A037388 _Clark Kimberling_