|
%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
|
