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A343603
For any positive number n, the balanced ternary representation of a(n) is obtained by right-rotating the balanced ternary representation of n until a nonzero digit appears again as the leftmost digit; a(0) = 0.
2
0, 1, -2, 3, 4, -7, -8, 11, -6, 9, 12, -5, 10, 13, -22, -25, 32, -21, -26, 33, -20, 29, 34, -19, -24, 35, -18, 27, 36, -17, 30, 37, -16, -23, 38, -15, 28, 39, -14, 31, 40, -67, -76, 95, -66, -79, 96, -65, 86, 97, -64, -75, 98, -63, -80, 99, -62, 87, 100, -61
OFFSET
0,3
COMMENTS
This sequence can be extended to negative indexes by setting a(-n) = -a(n) for any n > 0. We then obtain a permutation of the integers (Z) with inverse A343602 (after a similar extension to negative indexes).
LINKS
FORMULA
A065363(a(n)) = A065363(n).
A134021(a(n)) = A134021(n).
a^k(n) = n for k = A005812(n) (where a^k denotes the k-th iterate of a).
EXAMPLE
The first terms, in base 10 and in balanced ternary (where T denotes the digit -1), are:
n a(n) bter(n) bter(a(n))
-- ---- ------- ----------
0 0 0 0
1 1 1 1
2 -2 1T T1
3 3 10 10
4 4 11 11
5 -7 1TT T1T
6 -8 1T0 T01
7 11 1T1 11T
8 -6 10T T10
9 9 100 100
10 12 101 110
11 -5 11T T11
12 10 110 101
13 13 111 111
14 -22 1TTT T1TT
15 -25 1TT0 T01T
PROG
(PARI) a(n) = { my (d = [], t); while (n, d = concat(t = centerlift(Mod(n, 3)), d); n = (n-t)\3); forstep (k=#d, 1, -1, if (d[k], return (fromdigits(concat(d[k..#d], d[1..k-1]), 3)))); return (fromdigits(d, 3)) }
CROSSREFS
Cf. A005812, A065363, A134021, A139706 (binary variant), A343601 (ternary variant), A343602 (inverse).
Sequence in context: A357490 A333778 A272919 * A285506 A188190 A026808
KEYWORD
sign,base
AUTHOR
Rémy Sigrist, Apr 21 2021
STATUS
approved