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 A008449 #12 Jul 08 2025 01:04:20
%S A008449 1,90,1260,4920,13320,30492,55860,94680,156240,232770,332640,471240,
%T A008449 636480,835020,1098900,1391040,1720800,2181780,2614260,3118680,
%U A008449 3889962,4519140,5207760,6237000,7208640,8274510,9585000,10816560,12215520,14153760
%N A008449 Theta series of A_9 lattice.
%D A008449 J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 110.
%t A008449 terms = 24; f[q_] = LatticeData["A9", "ThetaSeriesFunction"][-I Log[q]/Pi]; Series[f[q], {q, 0, 2 terms - 1}] // CoefficientList[#, q]& // Round // DeleteCases[#, 0]& (* _Jean-François Alcover_, Jul 04 2017 *)
%K A008449 nonn
%O A008449 0,2
%A A008449 _N. J. A. Sloane_
%E A008449 More terms from _Sean A. Irvine_, Jun 12 2019