OFFSET
1,2
COMMENTS
Sequence contains all positive integers. Every positive integer except 1 can be term of this sequence only finitely many times (i.e., 8 is a term only for a(11) = 8). - Altug Alkan, Feb 28 2017
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
Ana Rechtman, Février 2017, 4e défi, Images des Mathématiques, CNRS, 2017.
FORMULA
MAPLE
Res:= NULL:
for n from 2 to 1000 do
p:= min(numtheory:-factorset(n));
if n mod p^2 = 0 then Res:= Res, n/p^2; fi
od:
Res; # Robert Israel, Feb 28 2017
MATHEMATICA
DeleteCases[Table[n/FactorInteger[n][[1, 1]]^2, {n, 2, 300}], k_ /; ! IntegerQ@ k] (* Michael De Vlieger, Feb 28 2017 *)
PROG
(PARI) lista(nn) = {for(n=2, nn, if (!(n % (p=factor(n)[1, 1]^2)), print1(n/p, ", ")); ); }
CROSSREFS
KEYWORD
nonn,look
AUTHOR
Michel Marcus, Feb 28 2017
STATUS
approved