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 A180410 #11 Sep 21 2022 12:33:55
%S A180410 1,2,3,4,5,6,7,8,9,1,1,12,13,14,15,16,17,18,19,2,12,2,23,24,25,26,27,
%T A180410 28,29,3,13,23,3,34,35,36,37,38,39,4,14,24,34,4,45,46,47,48,49,5,15,
%U A180410 25,35,45,5,56,57,58,59,6,16,26,36,46,56,6,67,68,69,7
%N A180410 Unique digits used in n in numerical order.
%C A180410 a(n) = A227362(n) - A151949(n). - _Reinhard Zumkeller_, Jul 09 2013
%H A180410 Reinhard Zumkeller, <a href="/A180410/b180410.txt">Table of n, a(n) for n = 1..10000</a>
%F A180410 a(n) = 0123456789 after any digits not appearing in n are removed.
%e A180410 a(93077) = 0379 = 379. Seven is only used once and the digits are sorted. The initial zero is not shown.
%p A180410 a:= n-> parse(cat(sort([{convert(n, base, 10)[]}[]])[])):
%p A180410 seq(a(n), n=1..70); # _Alois P. Heinz_, Sep 21 2022
%o A180410 (Haskell)
%o A180410 import Data.List (nub, sort)
%o A180410 a180410 = read . sort . nub . show :: Integer -> Integer
%o A180410 -- _Reinhard Zumkeller_, Jul 09 2013
%Y A180410 This is identical to A180409 with the zeros removed.
%K A180410 easy,nonn,base,look
%O A180410 1,2
%A A180410 _Dominick Cancilla_, Sep 02 2010