A319651 Largest number having in its ternary representation the same number of 0's, 1's and 2's as n.

0, 1, 2, 3, 4, 7, 6, 7, 8, 9, 12, 21, 12, 13, 22, 21, 22, 25, 18, 21, 24, 21, 22, 25, 24, 25, 26, 27, 36, 63, 36, 39, 66, 63, 66, 75, 36, 39, 66, 39, 40, 67, 66, 67, 76, 63, 66, 75, 66, 67, 76, 75, 76, 79, 54, 63, 72, 63, 66, 75, 72, 75, 78, 63, 66, 75, 66, 67, 76, 75, 76

Offset: 0

Author

Seiichi Manyama, Sep 25 2018

Keywords

• nonn
• base
• look
• easy

Links

• Seiichi Manyama, Table of n, a(n) for n = 0..6560

Crossrefs

Base b: A073138 (b=2), this sequence (b=3), A319720 (b=4), A319722 (b=5), A319723 (b=6), A319724 (b=7), this sequence (b=8), A319726 (b=9), A004186 (b=10).

Cf. A038574.

Programs

Mathematica

Table[FromDigits[ReverseSort[IntegerDigits[n, 3]], 3], {n, 0, 100}] (* Paolo Xausa, Aug 07 2024 *)

PARI

a(n) = fromdigits(vecsort(digits(n, 3),,4), 3); \\ Michel Marcus, Sep 25 2018

Python

from gmpy2 import digits
def A319651(n):
    return int(''.join(sorted(digits(n,3),reverse=True)),3) # Chai Wah Wu, Sep 26 2018

Ruby

def A(k, n)
  (0..n).map{|i| i.to_s(k).split('').sort.reverse.join.to_i(k)}
end
p A(3, 100)

Formula

n <= a(n) < 3n. - Charles R Greathouse IV, Aug 07 2024