A035860 Coordination sequence for A_34 lattice.

1, 1190, 354620, 47203730, 3563792960, 174181206542, 5997990984020, 154390001870810, 3103724917721540, 50409189277349630, 679545855082425212, 7772608216802526650, 76822363756617886400

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 (34, -561, 5984, -46376, 278256, -1344904, 5379616, -18156204, 52451256, -131128140, 286097760, -548354040, 927983760, -1391975640, 1855967520, -2203961430, 2333606220, -2203961430, 1855967520, -1391975640, 927983760, -548354040, 286097760, -131128140, 52451256, -18156204, 5379616, -1344904, 278256, -46376, 5984, -561, 34, -1).

Formula

Sum_{d=1..34} C(35, d)*C(m/2-1, d-1)*C(34-d+m/2, m/2), where norm m is always even.

Crossrefs

Sequence in context: A233640 A252643 A158735 * A290843 A298239 A299365

Adjacent sequences: A035857 A035858 A035859 * A035861 A035862 A035863

Keyword

nonn,easy

Author

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

Status

approved