A348706 Delete all 0's from ternary expansion of n.

1, 2, 1, 4, 5, 2, 7, 8, 1, 4, 5, 4, 13, 14, 5, 16, 17, 2, 7, 8, 7, 22, 23, 8, 25, 26, 1, 4, 5, 4, 13, 14, 5, 16, 17, 4, 13, 14, 13, 40, 41, 14, 43, 44, 5, 16, 17, 16, 49, 50, 17, 52, 53, 2, 7, 8, 7, 22, 23, 8, 25, 26, 7, 22, 23, 22, 67, 68, 23, 70, 71, 8, 25

Offset: 1

Author

Rémy Sigrist, Oct 30 2021

Keywords

• nonn
• base
• easy

Examples

			The first terms, in decimal and in base 3, are:
  n   a(n)  ter(n)  ter(a(n))
  --  ----  ------  ---------
   1     1       1          1
   2     2       2          2
   3     1      10          1
   4     4      11         11
   5     5      12         12
   6     2      20          2
   7     7      21         21
   8     8      22         22
   9     1     100          1
  10     4     101         11
  11     5     102         12
  12     4     110         11
  13    13     111        111
  14    14     112        112
  15     5     120         12
		

Links

• Rémy Sigrist, Table of n, a(n) for n = 1..6561

Crossrefs

Cf. A004719 (decimal analog), A032924 (fixed points), A038573 (binary analog).

Programs

Mathematica

a[n_] := FromDigits[DeleteCases[IntegerDigits[n, 3], 0], 3]; Array[a, 100] (* Amiram Eldar, Oct 31 2021 *)

PARI

a(n, base=3) = fromdigits(select(sign, digits(n, base)), base)

Python

from gmpy2 import digits
def A348706(n): return int(digits(n,3).replace('0',''),3) # Chai Wah Wu, Nov 02 2021

Formula

a(n) <= n with equality iff n belongs to A032924.