This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A045820 #19 Jul 25 2017 04:11:56
%S A045820 2,24,124,368,746,1288,2220,3536,4964,6904,9536,12112,15630,20592,
%T A045820 24588,29632,37472,43296,50492,61456,68724,79560,95404,104352,118226,
%U A045820 137392,148636,167920,191904,204712
%N A045820 Theta series of D8 lattice with respect to midpoint of edge.
%H A045820 Vincenzo Librandi, <a href="/A045820/b045820.txt">Table of n, a(n) for n = 0..1000</a>
%F A045820 G.f.: (1/2)*(theta_2^2*theta_3^6).
%F A045820 Expansion of q^(-1/2) * 2 * (eta(q^2)^7 / (eta(q)^3 * eta(q^4)^2))^4 in powers of q. - _Michael Somos_, Jul 24 2017
%t A045820 terms = 30; List @@ Normal[(1/2)*EllipticTheta[2, 0, z]^2*EllipticTheta[3, 0, z]^6 + O[z]^terms] /. z -> 1 (* _Jean-François Alcover_, Jul 06 2017 *)
%t A045820 a[ n_] := SeriesCoefficient[ EllipticTheta[ 2, 0, x^(1/2)]^4 EllipticTheta[ 3, 0, x]^4 / (8 Sqrt[x]), {x, 0, n}]; (* _Michael Somos_, Jul 24 2017 *)
%o A045820 (PARI) {a(n) = my(A); if( n<0, 0, A = x * O(x^n); 2 * polcoeff( (eta( x^2 + A)^7 / (eta( x + A)^3 * eta( x^4 + A)^2))^4, n))}; /* _Michael Somos_, Jul 24 2017 */
%Y A045820 Cf. A045822.
%K A045820 nonn
%O A045820 0,1
%A A045820 _N. J. A. Sloane_