A035778 Coordination sequence for C_41 lattice.

1, 3362, 1886082, 424744994, 51545165314, 3924107038242, 205809135461250, 7926934099341090, 234899820107413506, 5549249810903210786, 107487307512919088002, 1746399693272455238178, 24253916252710687817218

Offset

0,2

Links

Seiichi Manyama, Table of n, a(n) for n = 0..10000

R. Bacher, P. de la Harpe and B. Venkov, Séries de croissance et séries d'Ehrhart associées aux réseaux de racines, C. R. Acad. Sci. Paris, 325 (Series 1) (1997), 1137-1142.

J. H. Conway and N. J. A. Sloane, Low-Dimensional Lattices VII: Coordination Sequences, Proc. Royal Soc. London, A453 (1997), 2369-2389 (pdf).

Joan Serra-Sagrista, Enumeration of lattice points in l_1 norm, Inf. Proc. Lett. 76 (1-2) (2000) 39-44.

Formula

a(n) = [x^(2n)] ((1+x)/(1-x))^41.

Maple

seq(coeff(series(((1+x)/(1-x))^41, x, n+1), x, n), n=0..30, 2); # Muniru A Asiru, Aug 12 2018

Crossrefs

Cf. A035736.

Sequence in context: A207132 A175534 A233356 * A108002 A221332 A163044

Adjacent sequences: A035775 A035776 A035777 * A035779 A035780 A035781

Keyword

nonn,easy

Author

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

Extensions

Recomputed by N. J. A. Sloane, Nov 25 1998

Status

approved