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 A037407 #13 Aug 22 2021 09:22:31 %S A037407 1,2,3,4,5,6,7,8,10,20,30,40,50,60,70,80,91,136,158,172,182,227,263, %T A037407 273,318,354,364,405,415,425,435,445,450,451,452,453,454,455,456,457, %U A037407 458,465,475,485,536,546,627,637,683,718,728,801 %N A037407 Numbers k such that every base-9 digit of k is a base-10 digit of k. %H A037407 Reinhard Zumkeller, <a href="/A037407/b037407.txt">Table of n, a(n) for n = 1..10000</a> %t A037407 Select[Range[1000],SubsetQ[IntegerDigits[#],IntegerDigits[#,9]]&] (* _Harvey P. Dale_, May 01 2018 *) %o A037407 (Haskell) %o A037407 import Data.List ((\\), nub) %o A037407 a037407 n = a037407_list !! (n-1) %o A037407 a037407_list = filter f [1..] where %o A037407 f x = null $ nub (ds 9 x) \\ nub (ds 10 x) %o A037407 ds b x = if x > 0 then d : ds b x' else [] where (x', d) = divMod x b %o A037407 -- _Reinhard Zumkeller_, May 30 2013 %K A037407 nonn,base %O A037407 1,2 %A A037407 _Clark Kimberling_