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%I #23 Aug 05 2023 11:19:58
%S 12,18,20,24,28,36,40,44,45,48,50,52,54,56,60,63,68,72,75,76,80,84,88,
%T 90,92,96,98,99,100,104,108,112,116,117,120,124,126,132,135,136,140,
%U 144,147,148,150,152,153,156,160,162,164,168,171,172,175,176,180,184,188
%N Positive integers which are neither squarefree integers nor prime powers.
%H Michael De Vlieger, <a href="/A126706/b126706.txt">Table of n, a(n) for n = 1..10000</a>
%e 45 is in the sequence because 45=3^2*5, i.e., neither squarefree nor a prime power.
%p 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
%t Select[Range[200], Max @@ Last /@ FactorInteger[ # ] >1 && Length[FactorInteger[ # ]] > 1 &] (* _Ray Chandler_, Feb 17 2007 *)
%t Select[Range[200],!SquareFreeQ[#]&&!PrimePowerQ[#]&] (* _Harvey P. Dale_, Aug 05 2023 *)
%o (PARI) isok(k) = !issquarefree(k) && !isprimepower(k); \\ _Michel Marcus_, Nov 02 2022
%Y Cf. A005117, A000961, A059404.
%K nonn
%O 1,1
%A _Leroy Quet_, Feb 11 2007
%E Extended by _Emeric Deutsch_ and _Ray Chandler_, Feb 17 2007
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