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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 (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..13.

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 (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

Adjacent sequences:  A035852 A035853 A035854 * A035856 A035857 A035858

KEYWORD

nonn,easy

AUTHOR

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

STATUS

approved

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Last modified November 26 17:52 EST 2021. Contains 349343 sequences. (Running on oeis4.)