OFFSET
1,2
COMMENTS
a(n) = Max( core(k) : k=1,2,3,...,n ) where core(x) is the squarefree part of x (the smallest integer such that x*core(x) is a square).
LINKS
R. Zumkeller, Table of n, a(n) for n = 1..10000
MAPLE
A070321 := proc(n)
local a;
for a from n by -1 do
if issqrfree(a) then
return a;
end if;
end do:
end proc:
seq(A070321(n), n=1..100) ; # R. J. Mathar, May 25 2023
MATHEMATICA
a[n_] :=For[ k = n, True, k--, If[ SquareFreeQ[k], Return[k]]]; Table[a[n], {n, 1, 100}] (* Jean-François Alcover, Mar 27 2013 *)
gsfn[n_]:=Module[{k=n}, While[!SquareFreeQ[k], k--]; k]; Array[gsfn, 80] (* Harvey P. Dale, Mar 27 2013 *)
PROG
(PARI) a(n) = while (! issquarefree(n), n--); n; \\ Michel Marcus, Mar 18 2017
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Benoit Cloitre, May 11 2002
EXTENSIONS
New description from Reinhard Zumkeller, Oct 03 2002
STATUS
approved