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A035843
Coordination sequence for A_17 lattice.
0
1, 306, 23562, 822018, 16639974, 224676522, 2214405618, 16967926746, 105864434424, 556959705302, 2538818182782, 10244035242630, 37221177046410, 123490242018990, 378407481456870, 1081149205136382
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 (17, -136, 680, -2380, 6188, -12376, 19448, -24310, 24310, -19448, 12376, -6188, 2380, -680, 136, -17, 1).
FORMULA
Sum_{d=1..17} C(18, d)*C(m/2-1, d-1)*C(17-d+m/2, m/2), where norm m is always even.
CROSSREFS
Sequence in context: A221854 A221724 A023908 * A128477 A028680 A118282
KEYWORD
nonn,easy
AUTHOR
Joan Serra-Sagrista (jserra(AT)ccd.uab.es)
STATUS
approved