%I A007916
%S A007916 2,3,5,6,7,10,11,12,13,14,15,17,18,19,20,21,22,23,24,26,28,29,30,31,33,
%T A007916 34,35,37,38,39,40,41,42,43,44,45,46,47,48,50,51,52,53,54,55,56,57,58,
%U A007916 59,60,61,62,63,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,82,83
%N A007916 Not a perfect power.
%C A007916 These can be computed with a modified Sieve of Eratosthenes: (1) start 
               at n=2 (2) if n is not crossed out, then append n to the sequence 
               and cross out all powers of n (3) set n = n+1 and go to step 2 - 
               Sam Alexander (amnalexander(AT)yahoo.com), Dec 15 2003
%C A007916 A075802(a(n)) = 0. [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), 
               Mar 19 2009]
%C A007916 Or, the numbers with an even number of divisors. - Juri-Stepan Gerasimov 
               (2stepan(AT)rambler.ru), Oct 10 2009
%C A007916 The previous comment is wrong. For example, 27 has 4 divisors, but 27 
               is not in this sequence. [From T. D. Noe (noe(AT)sspectra.com), Nov 
               11 2009]
%D A007916 F. Smarandache, "Only Problems, not Solutions!", Xiquan Publ., Phoenix-Chicago, 
               1993
%H A007916 N. J. A. Sloane, <a href="b007916.txt">Table of n, a(n) for n = 1..9875</
               a>
%H A007916 F. Smarandache, <a href="http://www.gallup.unm.edu/~smarandache/OPNS.pdf">
               Only Problems, Not Solutions!</a>.
%t A007916 a = {}; Do[If[Apply[GCD, Transpose[FactorInteger[n]][[2]]] == 1, a = 
               Append[a, n]], {n, 2, 200}]; a
%o A007916 (MAGMA) [n : n in [2..1000] | not IsPower(n) ];
%Y A007916 Complement of A001597. Union of A052485 and A052486.
%Y A007916 A144338. [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), 
               Mar 19 2009]
%Y A007916 Cf. A000005. [From Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), Oct 
               10 2009]
%Y A007916 Sequence in context: A028769 A094784 A085971 this_sequence A052485 A109421 
               A065872
%Y A007916 Adjacent sequences: A007913 A007914 A007915 this_sequence A007917 A007918 
               A007919
%K A007916 nonn,new
%O A007916 1,1
%A A007916 R. Muller
%E A007916 More terms from Henry Bottomley (se16(AT)btinternet.com), Sep 12 2000