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%I #18 Jun 28 2023 14:45:42
%S 1,2,2,3,2,2,3,5,2,2,3,2,7,2,2,5,2,3,2,2,2,2,11,2,2,2,2,3,13,7,2,2,5,
%T 3,2,2,2,2,17,2,2,2,2,3,19,2,2,2,2,3,2,3,2,2,2,2,23,2,11,2,5,2,2,7,3,
%U 2,2,2,3,2,2,2,2,2,29,2,2,2,3,13,31,3,2,2
%N Smallest prime factors of 3-full numbers.
%H Reinhard Zumkeller, <a href="/A258568/b258568.txt">Table of n, a(n) for n = 1..10000</a> (corrected by Amiram Eldar)
%F a(n) = A020639(A036966(n)).
%F a(A258600(n)) = A000040(n) and a(m) != A000040(n) for m < A258600(n).
%t Table[If[Min[(f = FactorInteger[n])[[;; , 2]]] > 2 || n == 1, f[[1, 1]], Nothing], {n, 1, 30000}] (* _Amiram Eldar_, Feb 07 2023 *)
%o (Haskell)
%o a258568 = a020639 . a036966
%Y Cf. A036966, A020639, A258600, A258567, A258569, A258570, A258571.
%K nonn
%O 1,2
%A _Reinhard Zumkeller_, Jun 06 2015
%E Missing term a(78) inserted by _Amiram Eldar_, Feb 07 2023
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