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A005884 Theta series of f.c.c. lattice with respect to edge.

%I A005884 M0940 #25 Dec 01 2017 03:03:51
%S A005884 2,4,4,8,6,4,12,8,8,12,8,8,14,16,4,16,16,8,20,8,8,20,20,16,18,8,12,24,
%T A005884 16,12,20,24,8,28,16,8,32,20,16,16,18,20,24,24,16,24,24,8,40,20,12,40,
%U A005884 16,12,20,24,16,40,36,16,22,24,24,32,16,12,40,32,24,28,16,24,40,28,12
%N A005884 Theta series of f.c.c. lattice with respect to edge.
%D A005884 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A005884 G. C. Greubel, <a href="/A005884/b005884.txt">Table of n, a(n) for n = 0..1000</a>
%H A005884 N. J. A. Sloane and B. K. Teo, <a href="http://dx.doi.org/10.1063/1.449551">Theta series and magic numbers for close-packed spherical clusters</a>, J. Chem. Phys. 83 (1985) 6520-6534.
%H A005884 <a href="/index/Fa#fcc">Index entries for sequences related to f.c.c. lattice</a>
%F A005884 a(n) = 2*A045828(n).
%t A005884 QP = QPochhammer; s = 2 QP[q^2]^3*QP[q^4]^2/QP[q]^2 + O[q]^75; CoefficientList[s, q] (* _Jean-François Alcover_, Jul 04 2017 *)
%o A005884 (PARI) A045828(n)={ if(n<0, 0, A=x*O(x^n) ; polcoeff( eta(x^2+A)^3*eta(x^4+A)^2/eta(x+A)^2, n) ; ) ; }
%o A005884 A005884(n)={ 2*A045828(n) ; }
%o A005884 { for(n=0,100, print1(A005884(n),", ") ; ) ; } \\ _R. J. Mathar_, Jun 06 2007
%Y A005884 Cf. A045828.
%K A005884 nonn
%O A005884 0,1
%A A005884 _N. J. A. Sloane_
%E A005884 More terms from _R. J. Mathar_, Jun 06 2007