A103162 GCD of reverse(3^n) and reverse(3^(n+1)).

3, 9, 18, 18, 9, 9, 36, 9, 27, 27, 9, 9, 9, 9, 9, 27, 9, 63, 9, 9, 9, 9, 27, 18, 36, 9, 9, 18, 18, 18, 9, 9, 9, 9, 4941, 9, 9, 9, 9, 9, 9, 9, 9, 9, 144, 18, 9, 153, 333, 63, 18, 9, 27, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 18, 18, 9, 9, 18, 18, 18, 9, 9, 9, 9, 9, 9, 9, 9, 9, 81, 9, 9, 9, 9, 54

Offset

1,1

Links

Table of n, a(n) for n=1..89.

Formula

a(n) = GCD(A004167(n), A004167(n+1)).

Example

These common divisors are always divisible by 3.

Mathematica

rd[x_] :=FromDigits[Reverse[IntegerDigits[x]]] Table[GCD[rd[3^w], rd[3^(w+1)]], {w, 1, 100}]

Crossrefs

Cf. A004167.

Sequence in context: A103072 A109228 A355636 * A310331 A261952 A066006

Adjacent sequences: A103159 A103160 A103161 * A103163 A103164 A103165

Keyword

base,nonn

Author

Labos Elemer, Jan 25 2005

Status

approved