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Numbers N such that N modulo N's digitsum is a substring of N.
1

%I #16 Mar 10 2024 00:24:13

%S 10,11,13,14,17,19,20,22,23,26,28,30,31,32,33,35,37,39,40,41,44,46,50,

%T 53,55,60,62,64,66,69,70,71,73,77,80,82,88,90,91,93,96,99,100,101,102,

%U 103,104,106,108,109,110,113,118,119,120,121,122,123,125,127,129,131,136,139,140,142,145,149,150

%N Numbers N such that N modulo N's digitsum is a substring of N.

%C It seems that about third of all numbers belong to the sequence.

%H Jean-Marc Falcoz, <a href="/A302578/b302578.txt">Table of n, a(n) for n = 1..33333</a>

%e 10 has a digitsum of 1; 10/1 has 0 as remainder; 0 is a substring of 10;

%e 11 has a digitsum of 2; 11/2 has 1 as remainder; 1 is a substring of 11;

%e 12 has a digitsum of 3; 12/3 has 0 as remainder; 0 is not a substring of 12, thus 12 is not in the sequence;

%e 13 has a digitsum of 4; 13/4 has 1 as remainder; 1 is a substring of 13;

%e ...

%e 2018 has a digitsum of 11; 2018 modulo 11 is 5; 5 is not a substring of 2018, thus 2018 is not in the sequence;

%e etc.

%t Select[Range[200],SequenceCount[IntegerDigits[#],IntegerDigits[Mod[#,Total[ IntegerDigits[ #]]]]]>0&] (* _Harvey P. Dale_, Mar 03 2024 *)

%K nonn,base

%O 1,1

%A _Eric Angelini_ and _Jean-Marc Falcoz_, Apr 10 2018