%I A059269
%S A059269 4,9,12,18,20,25,28,32,36,44,45,49,50,52,60,63,68,72,75,76,84,90,92,96,
%T A059269 98,99,100,108,116,117,121,124,126,132,140,144,147,148,150,153,156,160,
%U A059269 164,169,171,172,175,180,188,196,198,200,204,207,212,220,224,225,228
%N A059269 Number of divisors d(n) is divisible by 3.
%C A059269 d(n) is divisible by 3 iff at least one prime in the prime factorization 
               of n has exponent of the form 3*m + 2. This sequence is an extension 
               of the sequence A038109 in which the numbers has at least one prime 
               with exponent 2 (the case of m = 0 here ) in their prime factorization.
%e A059269 a(7) = 28 because the number of divisors of 28 d(28) = 6
%p A059269 with(numtheory): for n from 1 to 1000 do if tau(n) mod 3 = 0 then printf(`%d,
               `,n) fi: od:
%Y A059269 A038109, A000005.
%Y A059269 Sequence in context: A034018 A047461 A089910 this_sequence A081619 A038109 
               A067259
%Y A059269 Adjacent sequences: A059266 A059267 A059268 this_sequence A059270 A059271 
               A059272
%K A059269 nonn,easy
%O A059269 0,1
%A A059269 Avi Peretz (njk(AT)netvision.net.il), Jan 24 2001
%E A059269 More terms from James A. Sellers (sellersj(AT)math.psu.edu), Jan 24 2001