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A035777
Coordination sequence for C_40 lattice.
1
1, 3200, 1708800, 366366080, 42340840960, 3070951360128, 153524473002240, 5639746542798720, 159505036253752320, 3599066875202445440, 66639047280436354816, 1035866362657624498560, 13775860435151438471680
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))^40.
MAPLE
seq(coeff(series(((1+x)/(1-x))^40, x, n+1), x, n), n=0..30, 2); # Muniru A Asiru, Aug 12 2018
CROSSREFS
Cf. A035735.
Sequence in context: A035896 A224646 A231203 * A108001 A212074 A023308
KEYWORD
nonn,easy
AUTHOR
Joan Serra-Sagrista (jserra(AT)ccd.uab.es)
EXTENSIONS
Recomputed by N. J. A. Sloane, Nov 25 1998
STATUS
approved