Search: id:A028260 Results 1-1 of 1 results found. %I A028260 %S A028260 1,4,6,9,10,14,15,16,21,22,24,25,26,33,34,35,36,38,39,40,46,49,51,54, %T A028260 55,56,57,58,60,62,64,65,69,74,77,81,82,84,85,86,87,88,90,91,93,94, %U A028260 95,96,100,104,106,111,115,118,119,121,122,123,126,129,132,133,134 %N A028260 Numbers n such that number of prime divisors of n (counted with multiplicity) is even; Liouville function lambda(n) (A008836) is positive. %C A028260 If n appears, p*n does not (p primes) . - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Jun 10 2006 %C A028260 The product of any two members of the this sequence, or any two members of the complement of this sequence (A026424) is a member of this sequence. The product of a member of this sequence and a member of A026424 is a member of A026424. The primitive elements of this sequence are the semiprimes (A001358). - Franklin T. Adams-Watters (FrankTAW(AT)Netscape.net), Nov 27 2006 %C A028260 A072978 is a subsequence. [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Sep 20 2008] %C A028260 A066829(a(n)) = 0. [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jun 26 2009] %H A028260 T. D. Noe, Table of n, a(n) for n=1..10000 %F A028260 Numbers n such that A069089(n)=A023900(n) - Benoit Cloitre (benoit7848c(AT)orange.fr), Apr 07 2002 %Y A028260 Cf. A008836, A026424. %Y A028260 Cf. A001222, A001358. %Y A028260 Cf. A145784. [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Oct 19 2008] %Y A028260 Sequence in context: A120329 A123249 A010428 this_sequence A085155 A063762 A001358 %Y A028260 Adjacent sequences: A028257 A028258 A028259 this_sequence A028261 A028262 A028263 %K A028260 nonn,easy,nice %O A028260 1,2 %A A028260 Dan Asimov (dan(AT)research.att.com) Search completed in 0.002 seconds