A035756 - OEIS

%I #23 Sep 06 2023 01:46:58

%S 1,722,87362,4298066,116323586,2029779538,25216532290,238745924050,

%T 1810015572994,11406058224594,61497762026306,290259969857618,

%U 1221518092836098,4652599114237778,16237772840882498,52462123239704786,158268201857667074,449093392401112274,1206082191029270850

%N Coordination sequence for C_19 lattice.

%H Seiichi Manyama, <a href="/A035756/b035756.txt">Table of n, a(n) for n = 0..10000</a>

%H 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 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 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 a(n) = [x^(2n)] ((1+x)/(1-x))^19.

%K nonn,easy

%O 0,2

%A Joan Serra-Sagrista (jserra(AT)ccd.uab.es)

%E Recomputed by _N. J. A. Sloane_, Nov 25 1998