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%I #31 Jul 07 2020 05:10:28
%S 1,1,2,3,5,6,7,10,11,13,14,15,17,19,21,22,23,26,29,30,31,33,34,35,37,
%T 38,39,41,42,43,46,47,51,53,55,57,58,59,61,62,65,66,67,69,70,71,73,74,
%U 77,78,79,82,83,85,86,87,89,91,93,94,95,97,101,102,103,105,106,107,109
%N Largest squarefree m <= sfn(n) such that m*sfn(n) is also squarefree, where sfn(n) is the n-th squarefree number.
%C gcd(a(n), spf(n)) = 1;
%C a(n+1) = sfn(n) for n < 106, but a(107) = 173 = sfn(105), as sfn(107)*sfn(106) = 177*174 = (3*59)*(2*3*29) is not squarefree.
%C The first n such that a(n+1) != A005117(n) (the squarefree integers) are 106, 258, 292, 368, 509, 515, 566, 653, 719, 807, 839, 882, 928, 992, .... - _Emmanuel Vantieghem_, Mar 10 2017
%H Emmanuel Vantieghem, <a href="/A076144/b076144.txt">Table of n, a(n) for n = 1..1000</a>
%t f[n_] := Module[{m = n}, While[! SquareFreeQ[m*n], m--]; m]; f /@ Select[ Range[110], SquareFreeQ] (* _Amiram Eldar_, Jul 07 2020 *)
%Y Cf. A005117, A077395.
%K nonn
%O 1,3
%A _Reinhard Zumkeller_, Oct 30 2002
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