A350229 a(n) is the sum of n and the balanced ternary digits in n.

0, 2, 2, 4, 6, 4, 6, 8, 8, 10, 12, 12, 14, 16, 12, 14, 16, 16, 18, 20, 20, 22, 24, 22, 24, 26, 26, 28, 30, 30, 32, 34, 32, 34, 36, 36, 38, 40, 40, 42, 44, 38, 40, 42, 42, 44, 46, 46, 48, 50, 48, 50, 52, 52, 54, 56, 56, 58, 60, 58, 60, 62, 62, 64, 66, 66, 68

Offset

0,2

Comments

The image of this sequence is the set of nonnegative even numbers (A005843).

Links

Table of n, a(n) for n=0..66.

Formula

a(n) = n + A065363(n).

a(n) = n iff n belongs to A174658.

Example

For n = 42:
- the balanced ternary representation of 42 is "1TTT0",
- so a(42) = 42 + 1 - 1 - 1 - 1 + 0 = 40.

Mathematica

Array[# + Total[If[First@ # == 0, Rest@ #, #] &[Prepend[IntegerDigits[#, 3], 0] //. {x___, y_, k_ /; k > 1, z___} :> {x, y + 1, k - 3, z}]] &, 70, 0] (* Michael De Vlieger, Jan 15 2022 *)

Prog

(PARI) a(n) = my (v=n, d); while (n, n=(n-d=[0, 1, -1][1+n%3])/3; v+=d); v

Crossrefs

See A062028, A092391, A230641 for similar sequences.

Cf. A005843, A065363, A174658 (fixed points).

Sequence in context: A073256 A166362 A050469 * A085730 A232065 A219741

Adjacent sequences: A350226 A350227 A350228 * A350230 A350231 A350232

Keyword

nonn,base,easy

Author

Rémy Sigrist, Jan 09 2022

Status

approved