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 A023920 #17 Jul 08 2025 17:22:23 %S A023920 1,0,0,0,18,0,0,72,0,240,252,0,0,504,0,0,1026,0,2160,1512,0,0,2664,0, %T A023920 0,3528,0,6720,5616,0,0,6552,0,0,9828,0,17520,11232,0,0,16380,0,0, %U A023920 17784,0,30240,24336,0,0,26208,0,0,35532,0,60480,37296,0,0,48780,0,0,50400,0 %N A023920 Theta series of A*_8 lattice. %D A023920 J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 114. %H A023920 Kok Seng Chua, <a href="https://doi.org/10.1090/S0002-9939-01-06080-4">The Root Lattice A*n and Ramanujan's Circular Summation of Theta Functions</a>, Proc. Amer. Math. Soc. 130 (2002), 1-8. %H A023920 G. Nebe and N. J. A. Sloane, <a href="http://www.math.rwth-aachen.de/~Gabriele.Nebe/LATTICES/As8.html">Home page for this lattice</a> %F A023920 E4(9z)+18*eta^12(9z)/eta^4(3z) (E4(9z) term because A*_8 contains E8 as a sublattice). - _Kok Seng Chua_, May 02 2000 %Y A023920 Cf. A004009, A033690. %K A023920 nonn,easy %O A023920 0,5 %A A023920 _N. J. A. Sloane_ %E A023920 More terms from _Kok Seng Chua_, Jul 29 2001