A343604 a(n) is the least number > n with the same sum of balanced ternary digits as n.

2, 3, 6, 7, 10, 15, 8, 9, 16, 11, 12, 19, 22, 31, 42, 17, 18, 23, 20, 21, 24, 25, 28, 43, 26, 27, 32, 29, 30, 33, 34, 37, 46, 35, 36, 49, 38, 39, 58, 67, 94, 123, 44, 45, 50, 47, 48, 51, 52, 55, 68, 53, 54, 59, 56, 57, 60, 61, 64, 69, 62, 63, 70, 65, 66, 73

Offset: 0

Author

Rémy Sigrist, Apr 22 2021

Keywords

• nonn
• base

Comments

This sequence can be extended to negative indexes by setting a(-n) = -A343605(n) for any n > 0.

Examples

			The first terms, in base 10 and in balanced ternary (where T denotes the digit -1), alongside A065363(n), are:
  n   a(n)  bter(n)  bter(a(n))  A065363(n)
  --  ----  -------  ----------  ----------
   0     2        0          1T           0
   1     3        1          10           1
   2     6       1T         1T0           0
   3     7       10         1T1           1
   4    10       11         101           2
   5    15      1TT        1TT0          -1
   6     8      1T0         10T           0
   7     9      1T1         100           1
   8    16      10T        1TT1           0
   9    11      100         11T           1
  10    12      101         110           2
  11    19      11T        1T01           1
  12    22      110        1T11           2
		

Links

• Rémy Sigrist, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A057168, A065363, A174658, A228915, A319021, A343605.

Programs

PARI

A065363(n) = { my (v=0, d); while (n, v+=d=centerlift(Mod(n,3)); n=(n-d)\3); v }
a(n) = my (s=A065363(n)); for (k=n+1, oo, if (s==A065363(k), return (k)))

Formula

a(9*n) = 9*n + 2.

a(A174658(n)) = A174658(n+1).