%I A028975
%S A028975 1,0,0,6,4,2,4,0,4,4,2,8,10,2,0,12,8,0,4,10,6,2,0,4,20,4,6,20,0,4,8,
%T A028975 8,8,8,4,2,24,4,2,16,6,4,2,12,16,10,4,8,22,0,4,40,6,0,10,8,0,4,4,22,
%U A028975 36,2,4,0,20,4,8,16,8,16,2,12,24,4,4,38,22,0,12,8,18,20,4,18,6,4,4
%N A028975 Theta series of quadratic form with Gram matrix [ 3, 1, 0; 1, 3, 1; 0, 
               1, 3 ].
%H A028975 John Cannon, <a href="b028975.txt">Table of n, a(n) for n = 0..10000</
               a>
%e A028975 1 + 6*q^3 + 4*q^4 + 2*q^5 + 4*q^6 + 4*q^8 + 4*q^9 + 2*q^10 + 8*q^11 + 
               10*q^12 + ...
%Y A028975 Sequence in context: A134300 A114062 A125214 this_sequence A145011 A086036 
               A019849
%Y A028975 Adjacent sequences: A028972 A028973 A028974 this_sequence A028976 A028977 
               A028978
%K A028975 nonn
%O A028975 0,4
%A A028975 N. J. A. Sloane (njas(AT)research.att.com).