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 A037402 #17 Aug 05 2021 07:01:58
%S A037402 1,2,3,4,5,6,8,16,24,32,40,48,57,85,94,106,114,133,142,163,171,196,
%T A037402 204,212,220,224,225,226,227,228,229,230,236,244,277,285,305,334,342,
%U A037402 385,392,401,540,546,547,550,597,620,629,646,688
%N A037402 Numbers k such that every base-7 digit of k is a base-8 digit of k.
%H A037402 Reinhard Zumkeller, <a href="/A037402/b037402.txt">Table of n, a(n) for n = 1..10000</a>
%t A037402 b7b8Q[n_]:=Module[{idn7=Union[IntegerDigits[n,7]]},Intersection[ idn7, Union[ IntegerDigits[n,8]]]==idn7]; Select[Range[700],b7b8Q] (* _Harvey P. Dale_, Dec 15 2013 *)
%o A037402 (Haskell)
%o A037402 import Data.List ((\\), nub)
%o A037402 a037402 n = a037402_list !! (n-1)
%o A037402 a037402_list = filter f [1..] where
%o A037402 f x = null $ nub (ds 7 x) \\ nub (ds 8 x)
%o A037402 ds b x = if x > 0 then d : ds b x' else [] where (x', d) = divMod x b
%o A037402 -- _Reinhard Zumkeller_, May 30 2013
%Y A037402 Cf. A007093, A007094.
%Y A037402 Cf. A037403, A037404.
%K A037402 nonn,base
%O A037402 1,2
%A A037402 _Clark Kimberling_