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%I #46 Dec 27 2021 11:08:26
%S 1,3,8,9,24,27,64,72,81,192,216,243,512,576,648,729,1536,1728,1944,
%T 2187,4096,4608,5184,5832,6561,12288,13824,15552,17496,19683,32768,
%U 36864,41472,46656,52488,59049,98304,110592,124416,139968,157464,177147,262144
%N Numbers of form 3^i*8^j, with i, j >= 0.
%C Subset of A003586 3-smooth numbers: numbers of the form 2^i*3^j with i, j >= 0. - _Daniel Forgues_, Feb 24 2011
%C Indices for which a term is a power of 3 are in A025699 and a power of 8 are in A025728- _Bernard Schott_, Dec 27 2021
%H Georg Fischer, <a href="/A025615/b025615.txt">Table of n, a(n) for n = 1..300</a>
%F Sum_{n>=1} 1/a(n) = 12/7. - _Amiram Eldar_, Feb 18 2021
%F From _Bernard Schott_, Dec 27 2021: (Start)
%F a(A025699(n)) = 3^(n-1).
%F a(A025728(n)) = 8^(n-1). (End)
%t lim = 262144; Select[Sort[Flatten[Table[3^i 8^j, {i, 0, Log[3, lim]}, {j, 0, Log[8, lim]}]]], # <=lim &] (* _T. D. Noe_, Mar 01 2012 *)
%o (PARI) list(lim)=my(v=List(), N); for(n=0, logint(lim\=1, 3), N=3^n; while(N<=lim, listput(v, N); N<<=3)); Set(v) \\ _Charles R Greathouse IV_, Jan 10 2018
%Y Cf. A003586, A025699, A025728.
%K easy,nonn
%O 1,2
%A _David W. Wilson_
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