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A102487 Numbers in base-12 representation that can be written with decimal digits.

%I A102487 #20 Feb 16 2025 08:32:55
%S A102487 0,1,2,3,4,5,6,7,8,9,12,13,14,15,16,17,18,19,20,21,24,25,26,27,28,29,
%T A102487 30,31,32,33,36,37,38,39,40,41,42,43,44,45,48,49,50,51,52,53,54,55,56,
%U A102487 57,60,61,62,63,64,65,66,67,68,69,72,73,74,75,76,77,78,79,80,81,84,85,86
%N A102487 Numbers in base-12 representation that can be written with decimal digits.
%C A102487 Numbers that are only in this sequence or only in A039274 but not in both are n= 131, 142, 275, 286, 419, 430 etc: see A039558. [From _R. J. Mathar_, Aug 30 2008]
%H A102487 Reinhard Zumkeller, <a href="/A102487/b102487.txt">Table of n, a(n) for n = 1..10000</a>
%H A102487 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Duodecimal.html">Duodecimal</a>
%H A102487 Wikipedia, <a href="http://en.wikipedia.org/wiki/Duodecimal">Duodecimal</a>
%t A102487 fQ[n_] := Last@ Union@ IntegerDigits[n, 12] < 10; Select[ Range[0, 86], fQ] (* _Robert G. Wilson v_, Apr 17 2012 *)
%o A102487 (PARI) {for(testn=0,87,
%o A102487 lgt=1;
%o A102487 for(i=1,1000,if(12^i > testn,lgt=i;break()));
%o A102487 atst=testn;pasr=1;
%o A102487 for(j=1,lgt,lasd=atst%12;
%o A102487 if(lasd<10,atst=(atst-lasd)/12,pasr=0;break()));
%o A102487 if(pasr==1,print1(testn,", ")))}
%o A102487 \\ _Douglas Latimer_, Apr 17 2012
%o A102487 (Haskell)
%o A102487 import Data.List (unfoldr)
%o A102487 a102487 n = a102487_list !! (n-1)
%o A102487 a102487_list = filter (all (< 10) . unfoldr (\x ->
%o A102487    if x == 0 then Nothing else Just $ swap $ divMod x 12)) [0..]
%o A102487 -- _Reinhard Zumkeller_, Apr 18 2011
%o A102487 (Python)
%o A102487 A102487_list = [int(str(x), 12) for x in range(10**6)] # _Chai Wah Wu_, Apr 09 2016
%Y A102487 Complement of A102488; A102489, A102491, A102493.
%Y A102487 Cf. A033048 (subsequence).
%K A102487 nonn,base
%O A102487 1,3
%A A102487 _Reinhard Zumkeller_, Jan 12 2005