

A059404


Numbers with different exponents in their prime factorizations.


28



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
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OFFSET

1,1


COMMENTS

Former name: Numbers k such that k/(largest power of squarefree kernel of k) is larger than 1.
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

440 is in the sequence because 440 = 2^3*5*11 and it has two distinct exponents, 3 and 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: A200511 A317711 A323055 * A303946 A242416 A317616
Adjacent sequences: A059401 A059402 A059403 * A059405 A059406 A059407


KEYWORD

nonn,easy


AUTHOR

Labos Elemer, Jul 18 2001


STATUS

approved



