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A126706 Positive integers which are neither squarefree integers nor prime powers. +0
1
12, 18, 20, 24, 28, 36, 40, 44, 45, 48, 50, 52, 54, 56, 60, 63, 68, 72, 75, 76, 80, 84, 88, 90, 92, 96, 98, 99, 100, 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 (list; graph; listen)
OFFSET

1,1

LINKS

Leroy Quet, Home Page (listed in lieu of email address)

EXAMPLE

45 is in the sequence because 45=3^2*5, i.e. neither squarefree nor a prime power.

MAPLE

with(numtheory): a:=proc(n) if mobius(n)=0 and nops(factorset(n))>1 then n else fi end: seq(a(n), n=1..230); - Emeric Deutsch (deutsch(AT)duke.poly.edu), Feb 17 2007

MATHEMATICA

Select[Range[200], Max @@ Last /@ FactorInteger[ # ] >1 && Length[FactorInteger[ # ]] > 1 &] (*Chandler*)

CROSSREFS

Cf. A005117, A000961, A059404.

Sequence in context: A007624 A036456 A102467 this_sequence A123711 A059404 A005101

Adjacent sequences: A126703 A126704 A126705 this_sequence A126707 A126708 A126709

KEYWORD

nonn

AUTHOR

Leroy Quet Feb 11 2007

EXTENSIONS

Extended by Emeric Deutsch (deutsch(AT)duke.poly.edu) and Ray Chandler (rayjchandler(AT)sbcglobal.net), Feb 17 2007

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Last modified November 30 13:13 EST 2009. Contains 167758 sequences.


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