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Numbers m such that m and 2*m have the same number of distinct digits in decimal representation.
4

%I #11 Jul 13 2013 12:03:24

%S 0,1,2,3,4,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,

%T 29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,56,

%U 57,58,59,61,72,83,94,100,101,102,103,104,105,107,108,109,110,111,112,113

%N Numbers m such that m and 2*m have the same number of distinct digits in decimal representation.

%C A043537(a(n)) = A043537(2*a(n)).

%H Reinhard Zumkeller, <a href="/A119798/b119798.txt">Table of n, a(n) for n = 1..10000</a>

%t snddQ[n_]:=Count[DigitCount[n],_?(#>0&)]==Count[DigitCount[2n], _?(#>0&)]; Select[Range[0,120],snddQ] (* _Harvey P. Dale_, Oct 07 2012 *)

%o (Haskell)

%o a119798 n = a119798_list !! (n-1)

%o a119798_list = f [0..] a043537_list a043537_list where

%o f (z:zs) (u:us) (v:_:vs) | u /= v = f zs us vs

%o | otherwise = z : f zs us vs

%o -- _Reinhard Zumkeller_, Jan 04 2012

%Y Cf. A119797, A119799.

%K nonn,base

%O 1,3

%A _Reinhard Zumkeller_, May 25 2006

%E Offset fixed by _Reinhard Zumkeller_, Jan 04 2012