

A060583


A ternary code related to the Tower of Hanoi.


4



0, 2, 1, 7, 6, 8, 5, 4, 3, 23, 22, 21, 18, 20, 19, 25, 24, 26, 16, 15, 17, 14, 13, 12, 9, 11, 10, 70, 69, 71, 68, 67, 66, 63, 65, 64, 54, 56, 55, 61, 60, 62, 59, 58, 57, 77, 76, 75, 72, 74, 73, 79, 78, 80, 50, 49, 48, 45, 47, 46, 52, 51, 53, 43, 42, 44, 41, 40, 39, 36, 38, 37
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

0,2


COMMENTS

Write n in base 3, then (working from left to right) if the kth digit of n is equal to the corresponding digit to the left of the kth digit of a(n) then this is the kth digit of a(n), otherwise the kth digit of a(n) is the element of {0,1,2} which has not just been compared, then read result as a base 3 number.


LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..6560
Index entries for sequences that are permutations of the natural numbers


FORMULA

a(n) = 3*a(floor(n/3)) + ((a(floor(n/3))n) mod 3) = 3*a(floor(n/3)) + A060582(n) with a(0)=0.


EXAMPLE

a(46) = 76 since 43 = 1201_3; this gives a first digit of 2(=310), a second digit of 2(=2=2), a third digit of 1(=320) and a fourth digit of 1(=1=1); 2211_3 = 76.


CROSSREFS

Cf. A060586, A060587 (inverse).
Sequence in context: A204912 A178049 A257577 * A246751 A295850 A078104
Adjacent sequences: A060580 A060581 A060582 * A060584 A060585 A060586


KEYWORD

base,nonn,look


AUTHOR

Henry Bottomley, Apr 04 2001


STATUS

approved



