A035859 Coordination sequence for A_33 lattice.

1, 1122, 315282, 39585282, 2820372522, 130174144914, 4236638107746, 103169215245426, 1964280056680326, 30250552830905946, 387159959112556938, 4209712158409065210, 39606467973324369810

Offset

0,2

Links

Table of n, a(n) for n=0..12.

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.

Index entries for linear recurrences with constant coefficients, signature (33, -528, 5456, -40920, 237336, -1107568, 4272048, -13884156, 38567100, -92561040, 193536720, -354817320, 573166440, -818809200, 1037158320, -1166803110, 1166803110, -1037158320, 818809200, -573166440, 354817320, -193536720, 92561040, -38567100, 13884156, -4272048, 1107568, -237336, 40920, -5456, 528, -33, 1).

Formula

Sum_{d=1..33} C(34, d)*C(m/2-1, d-1)*C(33-d+m/2, m/2), where norm m is always even.

Crossrefs

Sequence in context: A324404 A158729 A346219 * A105310 A200072 A261264

Adjacent sequences: A035856 A035857 A035858 * A035860 A035861 A035862

Keyword

nonn,easy

Author

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

Status

approved