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A212193 In ternary representation of n: a(n) = if n is pandigital then 3 else least digit not used.

%I A212193 #8 Feb 16 2025 08:33:17
%S A212193 1,0,0,2,0,0,1,0,0,2,2,3,2,0,0,3,0,0,1,3,1,3,0,0,1,0,0,2,2,3,2,2,3,3,
%T A212193 3,3,2,2,3,2,0,0,3,0,0,3,3,3,3,0,0,3,0,0,1,3,1,3,3,3,1,3,1,3,3,3,3,0,
%U A212193 0,3,0,0,1,3,1,3,0,0,1,0,0,2,2,3,2,2
%N A212193 In ternary representation of n: a(n) = if n is pandigital then 3 else least digit not used.
%C A212193 a(A032924(n)) = 0; a(A081605(n)) <> 0;
%C A212193 a(A031944(n)) = 3; a(A154314(n)) <> 3.
%H A212193 Reinhard Zumkeller, <a href="/A212193/b212193.txt">Table of n, a(n) for n = 0..10000</a>
%H A212193 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Ternary.html">Ternary</a>
%H A212193 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PandigitalNumber.html">Pandigital Number</a>
%H A212193 Wikipedia, <a href="http://en.wikipedia.org/wiki/Ternary_numeral_system">Ternary numeral system</a>
%H A212193 Wikipedia, <a href="http://en.wikipedia.org/wiki/Pandigital_number">Pandigital number</a>
%e A212193 .   0 ->   '0':   a(0) = 1
%e A212193 .   1 ->   '1':   a(1) = 0
%e A212193 .   2 ->   '2':   a(2) = 0
%e A212193 .   3 ->  '10':   a(3) = 2
%e A212193 .   4 ->  '11':   a(4) = 0
%e A212193 .   5 ->  '12':   a(5) = 0
%e A212193 .   6 ->  '20':   a(6) = 1
%e A212193 .   7 ->  '21':   a(7) = 0
%e A212193 .   8 ->  '22':   a(8) = 0
%e A212193 .   9 -> '100':   a(9) = 2
%e A212193 .  10 -> '101':  a(10) = 2
%e A212193 .  11 -> '102':  a(11) = 3  <-- 11 is the smallest 3-pandigital number
%e A212193 .  12 -> '110':  a(12) = 2
%e A212193 .  13 -> '111':  a(13) = 0
%e A212193 .  14 -> '112':  a(14) = 0
%e A212193 .  15 -> '120':  a(15) = 3.
%o A212193 (Haskell)
%o A212193 import Data.List (delete)
%o A212193 a212193 n = f n [0..3] where
%o A212193    f x ys | x <= 2    = head $ delete x ys
%o A212193           | otherwise = f x' $ delete d ys where (x',d) = divMod x 3
%Y A212193 Cf. A007089, A067898 (decimal).
%K A212193 nonn,base
%O A212193 0,4
%A A212193 _Reinhard Zumkeller_, May 04 2012