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Numbers whose smallest decimal digit is also the initial digit.
4

%I #13 Nov 21 2013 12:47:50

%S 0,1,2,3,4,5,6,7,8,9,11,12,13,14,15,16,17,18,19,22,23,24,25,26,27,28,

%T 29,33,34,35,36,37,38,39,44,45,46,47,48,49,55,56,57,58,59,66,67,68,69,

%U 77,78,79,88,89,99,111,112,113,114,115,116,117,118,119,121,122,123,124

%N Numbers whose smallest decimal digit is also the initial digit.

%C A054054(a(n)) = A000030(a(n));

%C the sequence differs from A009994, A032857 and A032898: a(65)=121 is not in A009994, a(58)=113 is not in A032857 and a(56)=111 is not in A032898.

%H Reinhard Zumkeller, <a href="/A072544/b072544.txt">Table of n, a(n) for n = 1..10000</a>

%t sddiQ[n_]:=Module[{idn=IntegerDigits[n]},First[idn]==Min[idn]]; Select[ Range[ 0,130],sddiQ] (* _Harvey P. Dale_, Oct 30 2011 *)

%o (Haskell)

%o a072544 n = a072544_list !! (n-1)

%o a072544_list = [x | x <- [0..], a054054 x == a000030 x]

%o -- _Reinhard Zumkeller_, Apr 25 2012

%Y Cf. A072543, A009994.

%K nonn,base

%O 1,3

%A _Reinhard Zumkeller_, Aug 04 2002