A305877 Numbers in base 3 reversed.

0, 1, 2, 1, 11, 21, 2, 12, 22, 1, 101, 201, 11, 111, 211, 21, 121, 221, 2, 102, 202, 12, 112, 212, 22, 122, 222, 1, 1001, 2001, 101, 1101, 2101, 201, 1201, 2201, 11, 1011, 2011, 111, 1111, 2111, 211, 1211, 2211, 21, 1021, 2021, 121, 1121, 2121, 221, 1221, 2221, 2

Offset: 0

Author

David F. Marrs, Jun 13 2018

Keywords

• nonn
• base
• easy

Examples

			11 is 102 in base 3, and reversing it gives 201 = a(11).
		

Links

• David F. Marrs, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A004086 (in base 10), A007089, A030102 (when converted in base 10).

Programs

Maple

a:= n-> parse(cat(convert(n, base, 3)[])):
seq(a(n), n=0..75);  # Alois P. Heinz, Jun 17 2018

Mathematica

Table[FromDigits@ Reverse@ IntegerDigits[n, 3], {n, 0, 54}] (* Giovanni Resta, Jun 13 2018 *)

PARI

a(n) = fromdigits(Vecrev(digits(n, 3)), 10); \\ Michel Marcus, Jun 13 2018

Formula

a(n) = A004086(A007089(n)). - Felix Fröhlich, Jun 14 2018