login
A035750
Coordination sequence for C_13 lattice.
3
1, 338, 19266, 454610, 6065410, 53972178, 354870594, 1847023698, 7988589570, 29746958930, 97926519106, 290835675858, 791675204866, 2000029880786, 4736845866818, 10603978331986, 22589850308610, 46054413896530, 90282306981698, 170866164067794, 313276266562818, 558092423954130
OFFSET
0,2
LINKS
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.
CROSSREFS
Sequence in context: A221799 A059976 A232782 * A186043 A107546 A235880
KEYWORD
nonn,easy
AUTHOR
Joan Serra-Sagrista (jserra(AT)ccd.uab.es)
EXTENSIONS
Recomputed by N. J. A. Sloane, Nov 25 1998
STATUS
approved