

A283069


A283050(n) divided by the square of its least prime factor.


2



1, 2, 1, 3, 4, 5, 6, 1, 3, 7, 8, 9, 10, 11, 5, 12, 1, 13, 14, 15, 7, 16, 17, 18, 19, 20, 9, 21, 22, 23, 24, 11, 25, 26, 27, 28, 29, 13, 30, 1, 31, 5, 32, 33, 15, 34, 35, 36, 37, 38, 17, 39, 40, 41, 42, 1, 19, 43, 7, 44, 45, 46, 47, 21, 48, 49, 50, 51, 23, 52, 53
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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

a(n) = A283050(n) / A020639(A283050(n))^2.  Altug Alkan, Feb 28 2017


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

Cf. A126773, A283050.
Sequence in context: A082470 A101204 A169808 * A304528 A175499 A181440
Adjacent sequences: A283066 A283067 A283068 * A283070 A283071 A283072


KEYWORD

nonn,look


AUTHOR

Michel Marcus, Feb 28 2017


STATUS

approved



