A344853 a(n) = n minus (sum of digits of n in base 3).

0, 0, 0, 2, 2, 2, 4, 4, 4, 8, 8, 8, 10, 10, 10, 12, 12, 12, 16, 16, 16, 18, 18, 18, 20, 20, 20, 26, 26, 26, 28, 28, 28, 30, 30, 30, 34, 34, 34, 36, 36, 36, 38, 38, 38, 42, 42, 42, 44, 44, 44, 46, 46, 46, 52, 52, 52, 54, 54, 54, 56, 56, 56, 60, 60, 60, 62, 62, 62

Offset

0,4

Comments

All terms are even.

In all sequences of the form f(n) = n minus (sum of digits of n in base b), every term appears b times consecutively. Here b = 3, hence terms are entries of A346502 repeated 3 times. - Bernard Schott, Jul 21 2021

Links

Michael De Vlieger, Table of n, a(n) for n = 0..10000

Formula

a(n) = n - A053735(n).

a(n) = 2 * A054861(n).

a(n) = 2 * A004128(floor(n/3)).

a(3*n) = a(3*n+1) = a(3*n+2).

Example

a(20) = 20 - (2 + 0 + 2) = 16 because 20 is written as 202 in base 3.

Mathematica

a[n_] := n - Plus @@ IntegerDigits[n, 3]; Array[a, 70, 0] (* Amiram Eldar, May 30 2021 *)

Prog

(PARI) a(n) = n - sumdigits(n, 3); \\ Michel Marcus, Jul 11 2021

Crossrefs

Cf. A011371 (in base 2), A066568 (in base 10).

Cf. A004128, A053735, A054861, A346502.

Sequence in context: A180019 A274496 A112801 * A173862 A089873 A275433

Adjacent sequences: A344850 A344851 A344852 * A344854 A344855 A344856

Keyword

base,easy,nonn

Author

Thomas König, May 30 2021

Status

approved