A072998 To get a(n), write n in balanced ternary notation (using only digits -1, 0, 1, -1), then change -1's to 0's, 0's to 1's, and 1's to 2's.

1, 2, 20, 21, 22, 200, 201, 202, 210, 211, 212, 220, 221, 222, 2000, 2001, 2002, 2010, 2011, 2012, 2020, 2021, 2022, 2100, 2101, 2102, 2110, 2111, 2112, 2120, 2121, 2122, 2200, 2201, 2202, 2210, 2211, 2212, 2220, 2221, 2222, 20000, 20001, 20002, 20010

Offset

0,2

Links

Table of n, a(n) for n=0..44.

Example

n balanced ternary a(n)
-----------------------
0........0...........1
1........1...........2
2......1,-1..........2,0
3.......1,0..........2,1
...
11 in base 10 = 11_10 = {1,1,-1} in balanced ternary = 1*3^2 + 1*3^1 - 1*3^0. Add 111 to {1,1,-1} to get a(11) = 220.

Crossrefs

Sequence in context: A303157 A338994 A217394 * A024629 A235500 A319953

Adjacent sequences: A072995 A072996 A072997 * A072999 A073000 A073001

Keyword

base,nonn

Author

Robert G. Wilson v, Aug 15 2002

Extensions

Corrected by Reinhard Zumkeller, Aug 18 2008

Edited by N. J. A. Sloane, Mar 31 2021

Status

approved