A212193 - OEIS

%I #7 Jul 13 2013 12:04:26

%S 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 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 0,3,0,0,1,3,1,3,0,0,1,0,0,2,2,3,2,2

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

%C a(A032924(n)) = 0; a(A081605(n)) <> 0;

%C a(A031944(n)) = 3; a(A154314(n)) <> 3.

%H Reinhard Zumkeller, <a href="/A212193/b212193.txt">Table of n, a(n) for n = 0..10000</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Ternary.html">Ternary</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PandigitalNumber.html">Pandigital Number</a>

%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Ternary_numeral_system">Ternary numeral system</a>

%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Pandigital_number">Pandigital number</a>

%e .   0 ->   '0':   a(0) = 1

%e .   1 ->   '1':   a(1) = 0

%e .   2 ->   '2':   a(2) = 0

%e .   3 ->  '10':   a(3) = 2

%e .   4 ->  '11':   a(4) = 0

%e .   5 ->  '12':   a(5) = 0

%e .   6 ->  '20':   a(6) = 1

%e .   7 ->  '21':   a(7) = 0

%e .   8 ->  '22':   a(8) = 0

%e .   9 -> '100':   a(9) = 2

%e .  10 -> '101':  a(10) = 2

%e .  11 -> '102':  a(11) = 3  <-- 11 is the smallest 3-pandigital number

%e .  12 -> '110':  a(12) = 2

%e .  13 -> '111':  a(13) = 0

%e .  14 -> '112':  a(14) = 0

%e .  15 -> '120':  a(15) = 3.

%o (Haskell)

%o import Data.List (delete)

%o a212193 n = f n [0..3] where

%o    f x ys | x <= 2    = head $ delete x ys

%o           | otherwise = f x' $ delete d ys where (x',d) = divMod x 3

%Y Cf. A007089, A067898 (decimal).

%K nonn,base

%O 0,4

%A _Reinhard Zumkeller_, May 04 2012