A337305 a(n) is the greatest number m not yet in the sequence such that the ternary expansions of n and of m have the same runs of consecutive equal digits (up to order but with multiplicity).

0, 1, 2, 3, 4, 7, 6, 5, 8, 9, 10, 21, 12, 13, 22, 19, 16, 25, 18, 15, 20, 11, 14, 23, 24, 17, 26, 27, 28, 63, 30, 37, 64, 57, 48, 75, 36, 31, 66, 39, 40, 67, 58, 49, 76, 55, 46, 69, 34, 43, 70, 73, 52, 79, 54, 45, 56, 33, 42, 65, 60, 61, 74, 29, 32, 59, 38, 41

Offset: 0

Author

Rémy Sigrist, Aug 22 2020

Keywords

• nonn
• base

Comments

This sequence is the base 3 analog of A337304.

This sequence is a self-inverse permutation of the nonnegative integers.

Examples

			For n = 144:
- the ternary representation of 144 is "12100",
- the corresponding runs of consecutive equal digits are: "1", "2", "1", "00",
- there are five numbers k with the same multiset of runs:
    k    ter(k)
    ---  -------
     86  "10012"
     88  "10021"
    136  "12001"
    144  "12100"
    190  "21001"
- so a(86) = 190,
     a(88) = 144,
     a(136) = 136,
     a(144) = 88,
     a(190) = 86.
		

Links

• Rémy Sigrist, Table of n, a(n) for n = 0..6561
• Rémy Sigrist, PARI program for A337305
• Index entries for sequences that are permutations of the natural numbers

Crossrefs

Cf. A331275, A337304.

Programs

PARI

See Links section.