%I M0006
%S 0,2,0,0,0,0,0,4,0,0,0,0,0,4,0,0,0,0,0,4,0,0,0,0,0,2,0,0,0,0,0,4,0,0,
%T 0,0,0,4,0,0,0,0,0,4,0,0,0,0,0,6,0,0,0,0,0,0,0,0,0,0,0,4,0,0,0,0,0,4,
%U 0,0,0,0,0,4,0,0,0,0,0,4,0,0,0,0,0,0,0,0,0,0,0,8,0,0,0,0,0,4,0,0,0,0,0,4,0
%N Theta series of hexagonal net with respect to midpoint of edge.
%D N. J. A. Sloane, Theta series and magic numbers for diamond and certain ionic crystal structures, J. Math. Phys. 28 (1987), 16531657.
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%p theta2:=x>add(2*x^((2*n1)^2/4),n=1..200): phi1:=x>theta2(x^(1/4))*theta2(x^(3/4))/2: seq(coeff(convert(series(phi1(x^4)phi1(x^12),x,200),polynom),x,n),n=0..200); # Herman Jamke (hermanjamke(AT)fastmail.fm), Feb 28 2008
%K easy,nonn
%O 0,2
%A _N. J. A. Sloane_
%E More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Feb 28 2008
