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A035857
Coordination sequence for A_31 lattice.
0
1, 992, 246512, 27390112, 1728939192, 70807488864, 2048715010256, 44450256810016, 755891034102316, 10424936982850656, 119820002520271088, 1173396885194646560, 9972151083876157960, 74688593871319112160
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 (31, -465, 4495, -31465, 169911, -736281, 2629575, -7888725, 20160075, -44352165, 84672315, -141120525, 206253075, -265182525, 300540195, -300540195, 265182525, -206253075, 141120525, -84672315, 44352165, -20160075, 7888725, -2629575, 736281, -169911, 31465, -4495, 465, -31, 1).
FORMULA
Sum_{d=1..31} C(32, d)*C(m/2-1, d-1)*C(31-d+m/2, m/2), where norm m is always even.
CROSSREFS
Sequence in context: A183973 A181601 A181707 * A028513 A373105 A267119
KEYWORD
nonn,easy
AUTHOR
Joan Serra-Sagrista (jserra(AT)ccd.uab.es)
STATUS
approved