A035750 Coordination sequence for C_13 lattice.

1, 338, 19266, 454610, 6065410, 53972178, 354870594, 1847023698, 7988589570, 29746958930, 97926519106, 290835675858, 791675204866, 2000029880786, 4736845866818, 10603978331986, 22589850308610, 46054413896530, 90282306981698, 170866164067794, 313276266562818, 558092423954130

Offset: 0

Author

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

Keywords

• nonn
• easy

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))^13.

Extensions

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