%I #15 May 08 2015 16:51:00
%S 4,10,11,13,14,20,21,22,24,25,31,32,37,40,43,44,51,54,57,64,65,76,82,
%T 84,87,89,92,98,100,101,104,110,111,112,114,116,121,122,124,125,127,
%U 128,137,140,141,142,144,145,148,149,151,154,158,172,177,191,196
%N Belgian-4 numbers.
%H Reinhard Zumkeller, <a href="/A106631/b106631.txt">Table of n, a(n) for n = 1..10000</a>
%t belgianQ[n_, k_] := If[n < k, False, Block[{id = Join[{0}, IntegerDigits@ n]}, MemberQ[ Accumulate@ id, Mod[n - k, Plus @@ id]] ]]; Select[ Range@ 199, belgianQ[#, 4] &] (* _Robert G. Wilson v_, May 06 2011 *)
%o (Haskell)
%o a106631 n = a106631_list !! (n-1)
%o a106631_list = filter belge4 [4..] where
%o belge4 x = x == (head $ dropWhile (< x) $
%o scanl (+) 4 $ cycle (map (read . return) $ show x))
%o -- _Reinhard Zumkeller_, May 08 2015
%Y See A106039 for definition and link.
%Y Belgian-k numbers, k=0..9: A106039, A106439, A106518, A106596, A106631, A106792, A107014, A107018, A107032, A107043.
%Y Cf. A257770.
%K base,easy,nonn
%O 1,1
%A _Eric Angelini_, Jun 07 2005
%E Offset changed by _Reinhard Zumkeller_, May 08 2015