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A035855
Coordination sequence for A_29 lattice.
0
1, 870, 189660, 18502290, 1026829680, 37041354030, 946156012020, 18170467948410, 274296114962940, 3368607034611630, 34588475083615740, 303610009666655370, 2320524189173327760, 15683018934278391990
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.
Index entries for linear recurrences with constant coefficients, signature (29, -406, 3654, -23751, 118755, -475020, 1560780, -4292145, 10015005, -20030010, 34597290, -51895935, 67863915, -77558760, 77558760, -67863915, 51895935, -34597290, 20030010, -10015005, 4292145, -1560780, 475020, -118755, 23751, -3654, 406, -29, 1).
FORMULA
Sum_{d=1..29} C(30, d)*C(m/2-1, d-1)*C(29-d+m/2, m/2), where norm m is always even.
CROSSREFS
Sequence in context: A158669 A206172 A205426 * A317806 A031783 A253167
KEYWORD
nonn,easy
AUTHOR
Joan Serra-Sagrista (jserra(AT)ccd.uab.es)
STATUS
approved