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%I #27 Feb 11 2021 03:55:49
%S 2,2,3,2,2,3,2,2,5,3,2,2,3,2,2,3,2,7,5,2,3,2,2,3,2,2,3,5,2,2,3,2,2,3,
%T 2,2,7,3,5,2,3,2,2,3,2,11,2,5,3,2,2,3,2,2,3,7,2,5,2,3,2,2,3,2,2,13,3,
%U 2,5,2,3,2,2,3,2,7,3,5,2,3,2,2,3,2,2,5,2,2,3,2,2,11,3,2,7,2,5,3,2,2,3
%N Largest multiple prime factor of the n-th nonsquarefree number (A013929).
%H Reinhard Zumkeller, <a href="/A046028/b046028.txt">Table of n, a(n) for n = 1..10000</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/GreatestPrimeFactor.html">Greatest Prime Factor</a>.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Squareful.html">Squareful</a>.
%F a(n) = A249740(A013929(n)). - _Amiram Eldar_, Feb 11 2021
%t Select[ FactorInteger[#]//Reverse, #[[2]]>1&, 1][[1, 1]]& /@ Select[ Range[300], !SquareFreeQ[#]& ] (* _Jean-François Alcover_, Nov 06 2012 *)
%o (Haskell)
%o a046028 n = a046028_list !! (n-1)
%o a046028_list = f 1 where
%o f x | null zs = f (x + 1)
%o | otherwise = (fst $ head zs) : f (x + 1)
%o where zs = reverse $ filter ((> 1) . snd) $
%o zip (a027748_row x) (a124010_row x)
%o -- _Reinhard Zumkeller_, Dec 29 2012
%Y Cf. A006530, A046027, A013929, A249740.
%Y Cf. A027748, A124010, A212177.
%K nonn,easy,nice
%O 1,1
%A _Eric W. Weisstein_
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