%I A030231
%S A030231 1,6,10,12,14,15,18,20,21,22,24,26,28,33,34,35,36,38,39,40,44,45,46,48,
%T A030231 50,51,52,54,55,56,57,58,62,63,65,68,69,72,74,75,76,77,80,82,85,86,87,
%U A030231 88,91,92,93,94,95,96,98,99,100,104,106,108,111,112,115,116,117,118,119
%N A030231 Number of distinct primes dividing n is even.
%C A030231 GCD[A008472(a[n]), A007947(a[n])]=1; see A014963. - Labos E. (labos(AT)ana.sote.hu), 
               Mar 26 2003
%C A030231 Superset of A007774. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), 
               Oct 23 2008]
%H A030231 T. D. Noe, <a href="b030231.txt">Table of n, a(n) for n=1..1000</a>
%F A030231 n such that sum(d|n, mu(d)*tau(d))=(-1)^omega(n)=+1 where mu(d)=A008683(d), 
               tau(d)=A000005(d) and omega(d)=A001221(d). n such that A023900(n)>
               0 - Benoit Cloitre, Dec 08 2002
%o A030231 (PARI) j=[]; for(n=1,200,x=omega(n); if(Mod(x,2)==0,j=concat(j,n))); 
               j
%Y A030231 Cf. A028260, A030230.
%Y A030231 Sequence in context: A024619 A106543 A007774 this_sequence A056760 A084227 
               A100658
%Y A030231 Adjacent sequences: A030228 A030229 A030230 this_sequence A030232 A030233 
               A030234
%K A030231 nonn,easy,nice
%O A030231 1,2
%A A030231 David W. Wilson (davidwwilson(AT)comcast.net)
%E A030231 Corrected by Dan Pritikin (pritikd(AT)muohio.edu), May 29 2002