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 A035750 #20 Sep 06 2023 01:40:58 %S A035750 1,338,19266,454610,6065410,53972178,354870594,1847023698,7988589570, %T A035750 29746958930,97926519106,290835675858,791675204866,2000029880786, %U A035750 4736845866818,10603978331986,22589850308610,46054413896530,90282306981698,170866164067794,313276266562818,558092423954130 %N A035750 Coordination sequence for C_13 lattice. %H A035750 Seiichi Manyama, <a href="/A035750/b035750.txt">Table of n, a(n) for n = 0..10000</a> %H A035750 R. Bacher, P. de la Harpe and B. Venkov, <a href="http://dx.doi.org/10.1016/S0764-4442(97)83542-2">Séries de croissance et séries d'Ehrhart associées aux réseaux de racines</a>, C. R. Acad. Sci. Paris, 325 (Series 1) (1997), 1137-1142. %H A035750 J. H. Conway and N. J. A. Sloane, Low-Dimensional Lattices VII: Coordination Sequences, Proc. Royal Soc. London, A453 (1997), 2369-2389 (<a href="http://neilsloane.com/doc/Me220.pdf">pdf</a>). %H A035750 Joan Serra-Sagrista, <a href="http://dx.doi.org/10.1016/S0020-0190(00)00119-8">Enumeration of lattice points in l_1 norm</a>, Inf. Proc. Lett. 76 (1-2) (2000) 39-44. %F A035750 a(n) = [x^(2n)] ((1+x)/(1-x))^13. %K A035750 nonn,easy %O A035750 0,2 %A A035750 Joan Serra-Sagrista (jserra(AT)ccd.uab.es) %E A035750 Recomputed by _N. J. A. Sloane_, Nov 25 1998