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 A037392 #8 May 30 2013 17:43:07 %S A037392 1,2,3,13,21,31,42,63,102,123,203,213,231,234,235,238,239,341,351,381, %T A037392 421,520,682,1013,1023,1024,1025,1026,1028,1029,1031,1032,1036,1037, %U A037392 1039,1040,1041,1042,1043,1044,1045,1053,1062 %N A037392 Every base 4 digit of n is a base 10 digit of n. %H A037392 Reinhard Zumkeller, <a href="/A037392/b037392.txt">Table of n, a(n) for n = 1..10000</a> %o A037392 (Haskell) %o A037392 import Data.List ((\\), nub) %o A037392 a037392 n = a037392_list !! (n-1) %o A037392 a037392_list = filter f [1..] where %o A037392 f x = null $ nub (ds 4 x) \\ nub (ds 10 x) %o A037392 ds b x = if x > 0 then d : ds b x' else [] where (x', d) = divMod x b %o A037392 -- _Reinhard Zumkeller_, May 30 2013 %Y A037392 Cf. A037387, A037388, A037389, A037390, A037391. %K A037392 nonn,base %O A037392 1,2 %A A037392 _Clark Kimberling_