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A059404 Numbers k such that k/(largest power of squarefree kernel of k) is larger than 1. 9
12, 18, 20, 24, 28, 40, 44, 45, 48, 50, 52, 54, 56, 60, 63, 68, 72, 75, 76, 80, 84, 88, 90, 92, 96, 98, 99, 104, 108, 112, 116, 117, 120, 124, 126, 132, 135, 136, 140, 144, 147, 148, 150, 152, 153, 156, 160, 162, 164, 168, 171, 172, 175, 176, 180, 184, 188, 189 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Complement of A072774 (powers of squarefree numbers).

Also numbers k = p(1)^alpha(1)* ... * p(r)^alpha(r) such that RootMeanSquare(alpha(1), ..., alpha(r)) is not an integer. - Ctibor O. Zizka, Sep 19 2008

LINKS

Donald Alan Morrison, Table of n, a(n) for n = 1..10000

Donald Alan Morrison, Sage program

FORMULA

A062760(a(n)) > 1, i.e., a(n)/(A007947(a(n))^A051904(a(n)) = a(n)/A062759(n) > 1.

EXAMPLE

k=440 is in the sequence because k = 2*2*2*5*11, its squarefree kernel = 110, quotient = 4 > 1.

PROG

(PARI) is(n)=#Set(factor(n)[, 2])>1 \\ Charles R Greathouse IV, Sep 18 2015

CROSSREFS

Cf. A003557, A007947, A051904, A062759, A062760.

Sequence in context: A126706 A123711 A200511 * A242416 A177425 A182854

Adjacent sequences:  A059401 A059402 A059403 * A059405 A059406 A059407

KEYWORD

nonn

AUTHOR

Labos Elemer, Jul 18 2001

STATUS

approved

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Last modified October 21 11:34 EDT 2017. Contains 293693 sequences.