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 A113600 Numbers K with 2n digits such that the two n-digit numbers formed by the alternate digits are divisors of K. 1

%I

%S 11,12,15,22,24,33,36,44,48,55,66,77,88,99,1012,1071,1100,1111,1155,

%T 1188,1200,1224,1275,1320,1350,1400,1500,1620,1664,1848,1980,1995,

%U 2016,2024,2079,2100,2150,2184,2200,2222,2310,2376,2400,2448,2500,2550,2640

%N Numbers K with 2n digits such that the two n-digit numbers formed by the alternate digits are divisors of K.

%H Harvey P. Dale, <a href="/A113600/b113600.txt">Table of n, a(n) for n = 1..1600</a>

%e 130788 is in the sequence because 130788 is divisible by 108 and 378.

%t addQ[n_]:=Module[{c=FromDigits/@Transpose[Partition[ IntegerDigits[n], 2]],a,b},a =First[c];b=Last[c];a!=0&&b!=0&&And@@Divisible[ n,{a,b}]]; Flatten[Table[Select[Range[10^(2n-1),10^(2n)-1],addQ],{n,2}]] (* _Harvey P. Dale_, Oct 21 2013 *)

%K base,easy,nonn

%O 1,1

%A _Amarnath Murthy_, Nov 09 2005

%E Corrected and extended by _Matthew Conroy_, Dec 18 2005

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Last modified June 20 10:13 EDT 2019. Contains 324234 sequences. (Running on oeis4.)