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%I #20 Oct 13 2023 14:20:47
%S 0,3,6,9,10,11,12,15,18,19,20,21,24,27,28,29,30,31,32,33,34,35,36,37,
%T 38,39,42,45,46,47,48,51,54,55,56,57,58,59,60,61,62,63,64,65,66,69,72,
%U 73,74,75,78,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100
%N Numbers having at least one 0 in their ternary representation.
%C Complement of A032924.
%C A212193(a(n)) <> 0. [_Reinhard Zumkeller_, May 04 2012]
%H Reinhard Zumkeller, <a href="/A081605/b081605.txt">Table of n, a(n) for n = 1..10000</a>
%t Select[Range[0,100],DigitCount[#,3,0]>0&] (* _Harvey P. Dale_, Aug 10 2021 *)
%o (Haskell)
%o import Data.List (findIndices)
%o a081605 n = a081605_list !! (n-1)
%o a081605_list = findIndices (/= 0) a212193_list
%o -- _Reinhard Zumkeller_, May 04 2012
%o (Python)
%o from itertools import count, islice
%o def A081605_gen(): # generator of terms
%o a = -1
%o for n in count(2):
%o b = int(bin(n)[3:],3) + (3**(n.bit_length()-1)-1>>1)
%o yield from range(a+1,b)
%o a = b
%o A081605_list = list(islice(A081605_gen(),30)) # _Chai Wah Wu_, Oct 13 2023
%Y Cf. A007089, A077267, A081607, A081606, A074940.
%K nonn,base
%O 1,2
%A _Reinhard Zumkeller_, Mar 23 2003
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