A035777 Coordination sequence for C_40 lattice.

1, 3200, 1708800, 366366080, 42340840960, 3070951360128, 153524473002240, 5639746542798720, 159505036253752320, 3599066875202445440, 66639047280436354816, 1035866362657624498560, 13775860435151438471680

Offset

0,2

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))^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

Adjacent sequences: A035774 A035775 A035776 * A035778 A035779 A035780

Keyword

nonn,easy

Author

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

Extensions

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

Status

approved