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A362089
The base-3 expansion of a(n) is obtained by inserting a zero before each nonzero digit of the base-3 expansion of n.
2
0, 1, 2, 3, 10, 11, 6, 19, 20, 9, 28, 29, 30, 91, 92, 33, 100, 101, 18, 55, 56, 57, 172, 173, 60, 181, 182, 27, 82, 83, 84, 253, 254, 87, 262, 263, 90, 271, 272, 273, 820, 821, 276, 829, 830, 99, 298, 299, 300, 901, 902, 303, 910, 911, 54, 163, 164, 165, 496
OFFSET
0,3
COMMENTS
This sequence is a permutation of A328727.
EXAMPLE
The first terms, in decimal and in base-3, are:
n a(n) ter(n) ter(a(n))
-- ---- ------ ---------
0 0 0 0
1 1 1 1
2 2 2 2
3 3 10 10
4 10 11 101
5 11 12 102
6 6 20 20
7 19 21 201
8 20 22 202
9 9 100 100
10 28 101 1001
11 29 102 1002
12 30 110 1010
PROG
(PARI) a(n) = { if (n==0, 0, n%3, 9*a(n\3) + n%3, 3*a(n/3)); }
(Python)
from gmpy2 import digits
def A362089(n): return int(digits(n, 3).replace('1', '01').replace('2', '02'), 3)
# Chai Wah Wu, Apr 12 2023
CROSSREFS
Cf. A007089 (ter(n)), A048678, A328727, A362090.
Sequence in context: A351413 A283436 A225558 * A301382 A288657 A055655
KEYWORD
nonn,base
AUTHOR
Rémy Sigrist, Apr 08 2023
STATUS
approved