login
A374362
a(n) is the least term t of A005836 such that n - t also belongs to A005836.
3
0, 0, 1, 0, 0, 1, 3, 3, 4, 0, 0, 1, 0, 0, 1, 3, 3, 4, 9, 9, 10, 9, 9, 10, 12, 12, 13, 0, 0, 1, 0, 0, 1, 3, 3, 4, 0, 0, 1, 0, 0, 1, 3, 3, 4, 9, 9, 10, 9, 9, 10, 12, 12, 13, 27, 27, 28, 27, 27, 28, 30, 30, 31, 27, 27, 28, 27, 27, 28, 30, 30, 31, 36, 36, 37, 36
OFFSET
0,7
COMMENTS
To compute a(n): in the ternary expansion of n, replace 1's by 0's and 2's by 1's.
LINKS
FORMULA
a(n) = A374361(n, 0).
a(n) = n - A374363(n).
a(n) >= 0 with equality iff n belongs to A374361.
a(n) = A005836(1 + A289814(n)).
EXAMPLE
The first terms, in decimal and in ternary, are:
n a(n) ter(n) ter(a(n))
-- ---- ------ ---------
0 0 0 0
1 0 1 0
2 1 2 1
3 0 10 0
4 0 11 0
5 1 12 1
6 3 20 10
7 3 21 10
8 4 22 11
9 0 100 0
10 0 101 0
11 1 102 1
12 0 110 0
13 0 111 0
14 1 112 1
15 3 120 10
PROG
(PARI) a(n) = fromdigits(apply(d -> [0, 0, 1][1+d], digits(n, 3)), 3)
(Python)
from gmpy2 import digits
def A374362(n): return int(digits(n, 3).replace('1', '0').replace('2', '1'), 3) # Chai Wah Wu, Jul 09 2024
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Rémy Sigrist, Jul 06 2024
STATUS
approved