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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 (list; graph; refs; listen; history; text; internal format)
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 A267119 A210315
KEYWORD
nonn,easy
AUTHOR
Joan Serra-Sagrista (jserra(AT)ccd.uab.es)
STATUS
approved

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Last modified February 26 17:19 EST 2024. Contains 370352 sequences. (Running on oeis4.)