A106439 Belgian-1 numbers.

1, 10, 11, 13, 16, 17, 21, 23, 41, 43, 56, 58, 74, 81, 91, 97, 100, 101, 106, 110, 111, 113, 115, 121, 122, 130, 131, 137, 142, 155, 157, 161, 170, 171, 172, 178, 179, 181, 184, 188, 193, 201

Offset: 1

Author

Eric Angelini, Jun 07 2005

Keywords

• base
• easy
• nonn

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Crossrefs

See A106039 for definition and link.

Belgian-k numbers, k=0..9: A106039, A106439, A106518, A106596, A106631, A106792, A107014, A107018, A107032, A107043.

Cf. A257770.

Programs

Haskell

a106439 n = a106439_list !! (n-1)
a106439_list = filter belge1 [1..] where
   belge1 x = x == (head $ dropWhile (< x) $
                    scanl (+) 1 $ cycle (map (read . return) $ show x))
-- Reinhard Zumkeller, May 08 2015

Mathematica

belgianQ[n_, k_] := If[n < k, False, Block[{id = Join[{0}, IntegerDigits@ n]}, MemberQ[ Accumulate@ id, Mod[n - k, Plus @@ id]] ]]; Select[ Range@ 202, belgianQ[#, 1] &] (* Robert G. Wilson v, May 06 2011 *)