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Numbers k with the property that the sum of the digits of k is a substring of k.
20

%I #38 Feb 13 2024 06:58:51

%S 0,1,2,3,4,5,6,7,8,9,10,20,30,40,50,60,70,80,90,100,109,119,129,139,

%T 149,159,169,179,189,199,200,300,400,500,600,700,800,900,910,911,912,

%U 913,914,915,916,917,918,919,1000,1009,1018,1027,1036,1045,1054,1063

%N Numbers k with the property that the sum of the digits of k is a substring of k.

%H Reinhard Zumkeller, <a href="/A052018/b052018.txt">Table of n, a(n) for n = 1..10000</a>

%t sdssQ[n_]:=Module[{idn=IntegerDigits[n],s,len},s=Total[idn];len= IntegerLength[ s]; MemberQ[Partition[idn,len,1],IntegerDigits[s]]]; Join[{0},Select[Range[1100],sdssQ]] (* _Harvey P. Dale_, Jan 02 2013 *)

%o (Haskell)

%o import Data.List (isInfixOf)

%o a052018 n = a052018_list !! (n-1)

%o a052018_list = filter f [0..] where

%o f x = show (a007953 x) `isInfixOf` show x

%o -- _Reinhard Zumkeller_, Jun 18 2013

%o (Python)

%o loop = (str(n) for n in range(399))

%o print([int(n) for n in loop if str(sum(int(k) for k in n)) in n]) # _Jonathan Frech_, Jun 05 2017

%Y Cf. A052019, A052020, A052021, A052022, A007953, A005349, A028834.

%Y Cf. A175688. - _Reinhard Zumkeller_, Aug 15 2010

%Y Cf. A055642, A004426.

%Y Cf. A119246, A138166.

%K nonn,base

%O 1,3

%A _Patrick De Geest_, Nov 15 1999