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 A107043 #16 May 08 2015 16:54:04
%S A107043 9,10,11,12,13,14,15,16,17,18,19,21,25,27,30,32,33,36,45,51,54,57,63,
%T A107043 67,69,72,81,83,90,93,99,100,101,102,104,105,108,109,110,111,115,117,
%U A107043 119,120,121,122,123,124,126,129,130,135,139,140,141,142,144,146,149,153
%N A107043 Belgian-9 numbers.
%H A107043 Reinhard Zumkeller, <a href="/A107043/b107043.txt">Table of n, a(n) for n = 1..10000</a>
%t A107043 belgianQ[n_, k_] := If[n < k, False, Block[{id = Join[{0}, IntegerDigits@ n]}, MemberQ[ Accumulate@ id, Mod[n - k, Plus @@ id]] ]]; Select[ Range@ 155, belgianQ[#, 9] &] (* _Robert G. Wilson v_, May 06 2011 *)
%o A107043 (Haskell)
%o A107043 a107043 n = a107043_list !! (n-1)
%o A107043 a107043_list = filter belge9 [9..] where
%o A107043 belge9 x = x == (head $ dropWhile (< x) $
%o A107043 scanl (+) 9 $ cycle (map (read . return) $ show x))
%o A107043 -- _Reinhard Zumkeller_, May 08 2015
%Y A107043 See A106039 for definition and link.
%Y A107043 Belgian-k numbers, k=0..9: A106039, A106439, A106518, A106596, A106631, A106792, A107014, A107018, A107032, A107043.
%Y A107043 Cf. A257770.
%K A107043 base,easy,nonn
%O A107043 1,1
%A A107043 _Eric Angelini_, Jun 07 2005
%E A107043 Offset changed by _Reinhard Zumkeller_, May 08 2015