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 A002490 #15 Feb 29 2020 20:29:40 %S A002490 1,0,2,1652,119550,1497328,16733124,108084480,588808172,2544811584, %T A002490 9516509988,31328336284,92876219432,252846150384,638250041288, %U A002490 1511780647680,3387237676950,7228330859840,14769380958438,29023337216604,55108233751768,101433859301088 %N A002490 Theta series of 27-dimensional unimodular lattice with root system A_1 and a parity vector of norm 3. %D A002490 R. Bacher and B. B. Venkov, Réseaux entiers unimodulaires sans racine en dimension 27 et 28, in Réseaux euclidiens, designs sphériques et formes modulaires, pp. 212-267, Enseignement Math., Geneva, 2001. %H A002490 R. Bacher and B. B. Venkov, <a href="https://www-fourier.univ-grenoble-alpes.fr/?q=fr/content/reseaux-entiers-unimodulaires-sans-racine-en-dimension-27-et-28">Réseaux entiers unimodulaires sans racine en dimension 27 et 28</a> %F A002490 G.f.: theta3^27 - 54*theta3^19*delta8 + 218*theta3^11*delta8^2 - 1024*theta3^3*delta8^3 where theta3 = A000122 and delta8 = A002408. - _Sean A. Irvine_, Feb 28 2020 %Y A002490 Cf. A000122, A002408, A002434. %K A002490 nonn %O A002490 0,3 %A A002490 _N. J. A. Sloane_ %E A002490 More terms from _Sean A. Irvine_, Feb 28 2020