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A035779
Coordination sequence for C_42 lattice.
1
1, 3528, 2076816, 490681688, 62456027424, 4985149915368, 273998113272240, 11053262513080440, 342841481215636032, 8471578904288191496, 171504713146698879696, 2910051399340259388312, 42170689218812731525984
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))^42.
MAPLE
seq(coeff(series(((1+x)/(1-x))^42, x, n+1), x, n), n=0..30, 2); # Muniru A Asiru, Aug 12 2018
CROSSREFS
Cf. A035737.
Sequence in context: A064256 A232555 A330841 * A108003 A176139 A354542
KEYWORD
nonn,easy
AUTHOR
Joan Serra-Sagrista (jserra(AT)ccd.uab.es)
EXTENSIONS
Recomputed by N. J. A. Sloane, Nov 25 1998
STATUS
approved