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A287442 Numbers k = concat( x, y ), not ending in 0, such that  x * y divides k. 1

%I

%S 11,12,15,24,36,101,102,104,105,125,208,306,315,735,1001,1002,1004,

%T 1005,1008,1025,1125,1352,1734,2016,3006,3015,3024,3375,6048,7007,

%U 7056,9072,10001,10002,10004,10005,10008,10016,10025,10125,10625,11011,13013,14112,18144

%N Numbers k = concat( x, y ), not ending in 0, such that x * y divides k.

%C Numbers ending in zero are not listed because of the form a(n) * 10^k, with k>0.

%H Paolo P. Lava, <a href="/A287442/a287442.txt">First 250 terms with their ratios</a>

%e 36 = concat(3,6) and 36 / (3*6) = 2;

%e 3375 = concat(3,375) and 3375 / (3*375) = 3;

%e 18144 = concat(18,144) and 18144 / (18*144) = 7.

%p P:=proc(q) local a,k,n; for n from 1 to q do if not n mod 10=0 then

%p for k from 1 to ilog10(n) do a:=n/((n mod 10^k)*trunc(n/10^k));

%p if type(a,integer) then print(n); break; fi; od; fi; od; end: P(10^9);

%t cxyQ[n_]:=Module[{idn=IntegerDigits[n]},idn[[-1]]!=0&&AnyTrue[ Table[ FromDigits/@TakeDrop[idn,k],{k,Length[idn]-1}],Divisible[n, Times@@#]&]]; Select[Range[20000],cxyQ] (* The program uses the AnyTrue function from Mathematica version 10 *)(* _Harvey P. Dale_, Mar 09 2018 *)

%K nonn,base,easy

%O 1,1

%A _Paolo P. Lava_, May 25 2017

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Last modified July 21 18:06 EDT 2019. Contains 325198 sequences. (Running on oeis4.)