login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A126706 Positive integers which are neither squarefree integers nor prime powers. 13
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; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Michael De Vlieger, Table of n, a(n) for n = 1..10000

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, Feb 17 2007

MATHEMATICA

Select[Range[200], Max @@ Last /@ FactorInteger[ # ] >1 && Length[FactorInteger[ # ]] > 1 &] (* Ray Chandler, Feb 17 2007 *)

CROSSREFS

Cf. A005117, A000961, A059404.

Sequence in context: A007624 A036456 A102467 * A123711 A200511 A317711

Adjacent sequences:  A126703 A126704 A126705 * A126707 A126708 A126709

KEYWORD

nonn

AUTHOR

Leroy Quet, Feb 11 2007

EXTENSIONS

Extended by Emeric Deutsch and Ray Chandler, Feb 17 2007

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 28 21:37 EDT 2020. Contains 334690 sequences. (Running on oeis4.)