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A085239 Sort the numbers 2^i and 3^j. Then a(n) is the base of the n-th term. Set a(1)=1. 6

%I

%S 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,

%T 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,

%U 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

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

%H T. D. Noe, <a href="/A085239/b085239.txt">Table of n, a(n) for n=1..500</a>

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

%F For n > 1: a(n) = 2 + A006899(n) mod 2. - _Reinhard Zumkeller_, Oct 09 2013

%t m = 40;

%t Join[{1}, If[Total[IntegerDigits[#, 2]] == 1, 2, 3]& /@ Union[3^Range[m], 2^Range[Length[IntegerDigits[3^m, 2]] - 1]]] (* _Jean-Fran├žois Alcover_, Oct 07 2021 *)

%o (Haskell)

%o a085239 1 = 1

%o a085239 n = a006899 n `mod` 2 + 2 -- _Reinhard Zumkeller_, Oct 09 2013

%Y Cf. A000079, A000244.

%Y Cf. A006899, A085238.

%K nonn

%O 1,2

%A _Reinhard Zumkeller_, Jun 22 2003

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Last modified October 24 20:35 EDT 2021. Contains 348233 sequences. (Running on oeis4.)