%I #10 Oct 11 2023 03:54:20

%S 2,4,6,10,14,18,20,22,26,28,30,34,38,42,44,46,50,52,54,58,62,66,68,70,

%T 74,76,78,82,86,90,92,94,98,100,102,106,110,114,116,118,122,124,126,

%U 130,134,138,140,142,146,148,150,154,158,162,164,166,170,172,174,178,182,186,188

%N Numbers with the same number of odd / even, refactorable divisors.

%C All the terms are even. Conjecture: The sequence a(n)/2 is the complement of A157932 (verified for a(n) < 4*10^7). - _Amiram Eldar_, Oct 11 2023

%H Amiram Eldar, <a href="/A345211/b345211.txt">Table of n, a(n) for n = 1..10000</a>

%e 18 is in the sequence since it has 2 odd and 2 even, refactorable divisors: 1, 2, 9, and 18.

%t q[n_] := DivisorSum[n, (-1)^# &, Divisible[#, DivisorSigma[0, #]] &] == 0; Select[Range[2, 200, 2], q] (* _Amiram Eldar_, Oct 11 2023 *)

%o (PARI) is(n) = (n%2)! && sumdiv(n, d, (-1)^d * !(d % numdiv(d))) == 0; \\ _Amiram Eldar_, Oct 11 2023

%Y Cf. A033950, A157932, A336041.

%K nonn

%O 1,1

%A _Wesley Ivan Hurt_, Jun 10 2021