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A035848 Coordination sequence for A_22 lattice. 0
1, 506, 64262, 3670018, 120177024, 2584888350, 39868752506, 468969729382, 4403475647758, 34183012888134, 225524301678170, 1292986222651646, 6559731002608432, 29893343687161218, 123905004120349254 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

REFERENCES

R. Bacher, P. de la Harpe and B. Venkov, Series de croissance et series d'Ehrhart associees aux reseaux de racines, C. R. Acad. Sci. Paris, 325 (Series 1) (1997), 1137-1142.

J. Serra-Sagrista, Enumeration of lattice points in l_1 norm, Information Processing Letters, 76, no. 1-2 (2000), 39-44.

LINKS

Table of n, a(n) for n=0..14.

J. H. Conway and N. J. A. Sloane, Low-Dimensional Lattices VII: Coordination Sequences, Proc. Royal Soc. London, A453 (1997), 2369-2389 (pdf).

Index entries for linear recurrences with constant coefficients, signature (22, -231, 1540, -7315, 26334, -74613, 170544, -319770, 497420, -646646, 705432, -646646, 497420, -319770, 170544, -74613, 26334, -7315, 1540, -231, 22, -1).

FORMULA

Sum_{d=1..22} C(23, d)*C(m/2-1, d-1)*C(22-d+m/2, m/2), where norm m is always even.

CROSSREFS

Sequence in context: A122267 A204946 A023913 * A028685 A152524 A236004

Adjacent sequences:  A035845 A035846 A035847 * A035849 A035850 A035851

KEYWORD

nonn,easy

AUTHOR

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

STATUS

approved

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Last modified October 25 03:28 EDT 2021. Contains 348237 sequences. (Running on oeis4.)