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A305634 Even numbers that are not perfect powers.

%I A305634 #19 Jan 24 2019 18:34:22
%S A305634 2,6,10,12,14,18,20,22,24,26,28,30,34,38,40,42,44,46,48,50,52,54,56,
%T A305634 58,60,62,66,68,70,72,74,76,78,80,82,84,86,88,90,92,94,96,98,102,104,
%U A305634 106,108,110,112,114,116,118,120,122,124,126,130,132,134,136,138
%N A305634 Even numbers that are not perfect powers.
%C A305634 Perfect powers are of the form m^k where m > 0 and k > 1 (A001597).
%H A305634 Robert Israel, <a href="/A305634/b305634.txt">Table of n, a(n) for n = 1..10000</a>
%F A305634 A005843 \ A001597. - _Eric Chen_, Jun 14 2018
%e A305634 10 is in the sequence since it is even and is not a power of an integer.  17 is not in the sequence since it is odd, and 36 is not in the sequence since it is a power of an integer (36 = 6^2).
%p A305634 N:= 1000:
%p A305634 S:={seq(i,i=2..N,2)} minus {seq(seq(e^m,m=2..floor(log[e](N))),e=2..floor(sqrt(N)),2)}:
%p A305634 sort(convert(S,list)); # _Robert Israel_, Jan 24 2019
%t A305634 radQ[n_]:=Or[n==1,GCD@@FactorInteger[n][[All,2]]==1];
%t A305634 Select[Range[200],EvenQ[#]&&radQ[#]&]
%o A305634 (PARI) isok(n) = !(n % 2) && !ispower(n); \\ _Michel Marcus_, Jun 08 2018
%Y A305634 Cf. A001597, A005117, A007916, A039956.
%Y A305634 Cf. A305630, A305631, A305632, A305633, A305635.
%Y A305634 Cf. A005843, A001597.
%K A305634 nonn
%O A305634 1,1
%A A305634 _Gus Wiseman_, Jun 07 2018