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A126706
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Positive integers which are neither squarefree integers nor prime powers.
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101
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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
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OFFSET
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1,1
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LINKS
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EXAMPLE
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45 is in the sequence because 45=3^2*5, i.e., neither squarefree nor a prime power.
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MAPLE
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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
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MATHEMATICA
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Select[Range[200], Max @@ Last /@ FactorInteger[ # ] >1 && Length[FactorInteger[ # ]] > 1 &] (* Ray Chandler, Feb 17 2007 *)
Select[Range[200], !SquareFreeQ[#]&&!PrimePowerQ[#]&] (* Harvey P. Dale, Aug 05 2023 *)
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PROG
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(PARI) isok(k) = !issquarefree(k) && !isprimepower(k); \\ Michel Marcus, Nov 02 2022
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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