OFFSET
1,3
COMMENTS
gcd(a(n), spf(n)) = 1;
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.
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
LINKS
Emmanuel Vantieghem, Table of n, a(n) for n = 1..1000
MATHEMATICA
f[n_] := Module[{m = n}, While[! SquareFreeQ[m*n], m--]; m]; f /@ Select[ Range[110], SquareFreeQ] (* Amiram Eldar, Jul 07 2020 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Oct 30 2002
STATUS
approved