A085239 Sort the numbers 2^i and 3^j. Then a(n) is the base of the n-th term. Set a(1)=1.

1, 2, 3, 2, 2, 3, 2, 3, 2, 2, 3, 2, 3, 2, 2, 3, 2, 2, 3, 2, 3, 2, 2, 3, 2, 3, 2, 2, 3, 2, 2, 3, 2, 3, 2, 2, 3, 2, 3, 2, 2, 3, 2, 3, 2, 2, 3, 2, 2, 3, 2, 3, 2, 2, 3, 2, 3, 2, 2, 3, 2, 2, 3, 2, 3, 2, 2, 3, 2, 3, 2, 2, 3, 2, 3, 2, 2, 3, 2, 2, 3, 2, 3, 2, 2, 3, 2, 3, 2, 2, 3, 2, 2, 3, 2, 3, 2, 2, 3, 2, 3, 2

Offset

1,2

Comments

The density of 2's in this sequence is log(3)/log(6). The density of 3's in this sequence is log(2)/log(6). - Jennifer Buckley, Apr 24 2024

Links

T. D. Noe, Table of n, a(n) for n=1..500

Formula

A006899(n) = a(n)^A085238(n).

For n > 1: a(n) = 2 + A006899(n) mod 2. - Reinhard Zumkeller, Oct 09 2013

Mathematica

m = 40;
Join[{1}, If[Total[IntegerDigits[#, 2]] == 1, 2, 3]& /@ Union[3^Range[m], 2^Range[Length[IntegerDigits[3^m, 2]] - 1]]] (* Jean-François Alcover, Oct 07 2021 *)

Prog

(Haskell)
a085239 1 = 1
a085239 n = a006899 n `mod` 2 + 2  -- Reinhard Zumkeller, Oct 09 2013
(PARI) upto(L) = my(v2=2, v3=1, r=List(1)); while(v3<L, v3*=3; while(v2<v3 && v2<=L, listput(~r, 2); v2*=2); v3<=L && listput(~r, 3)); Vec(r); \\ Ruud H.G. van Tol, May 10 2024

Crossrefs

Cf. A000079, A000244.

Cf. A006899, A085238.

Cf. A152683, A152935.

Sequence in context: A116909 A333853 A182006 * A374369 A242872 A329362

Adjacent sequences: A085236 A085237 A085238 * A085240 A085241 A085242

Keyword

nonn

Author

Reinhard Zumkeller, Jun 22 2003

Status

approved