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A179276 Largest 3-smooth number <= n.

%I A179276 #17 Aug 27 2025 06:32:42
%S A179276 1,2,3,4,4,6,6,8,9,9,9,12,12,12,12,16,16,18,18,18,18,18,18,24,24,24,
%T A179276 27,27,27,27,27,32,32,32,32,36,36,36,36,36,36,36,36,36,36,36,36,48,48,
%U A179276 48,48,48,48,54,54,54,54,54,54,54,54,54,54,64,64,64,64,64,64,64,64,72,72
%N A179276 Largest 3-smooth number <= n.
%H A179276 David A. Corneth, <a href="/A179276/b179276.txt">Table of n, a(n) for n = 1..10000</a>
%F A179276 A065333(a(n)) = 1;
%F A179276 a(A003586(n)) = A003586(n);
%F A179276 A065331(n) <= a(n).
%F A179276 a(n) = A003586(A071521(n)). - _Ridouane Oudra_, Aug 24 2025
%t A179276 smooth3Q[n_] := FactorInteger[n][[-1, 1]] <= 3;
%t A179276 a[n_] := For[k = n, True, k--, If[smooth3Q[k], Return[k]]];
%t A179276 Table[a[n], {n, 1, 100}] (* _Jean-François Alcover_, Oct 14 2021 *)
%Y A179276 Cf. A003586, A065331, A065333, A081328, A071521.
%K A179276 nonn,changed
%O A179276 1,2
%A A179276 _Reinhard Zumkeller_, Jul 07 2010
%E A179276 Definition corrected by _Georg Fischer_, Aug 05 2021