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A035869
Coordination sequence for A_43 lattice.
0
1, 1892, 895862, 189126212, 22576717592, 1737436100444, 93714991099466, 3755363400343676, 116715616046942726, 2908413970471697116, 59664124959218615418, 1029601387463447404860, 15216687141326909030760
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 (43, -903, 12341, -123410, 962598, -6096454, 32224114, -145008513, 563921995, -1917334783, 5752004349, -15338678264, 36576848168, -78378960360, 151532656696, -265182149218, 421171648758, -608359048206, 800472431850, -960566918220, 1052049481860, -1052049481860, 960566918220, -800472431850, 608359048206, -421171648758, 265182149218, -151532656696, 78378960360, -36576848168, 15338678264, -5752004349, 1917334783, -563921995, 145008513, -32224114, 6096454, -962598, 123410, -12341, 903, -43, 1).
FORMULA
Sum_{d=1..43} C(44, d)*C(m/2-1, d-1)*C(43-d+m/2, m/2), where norm m is always even.
CROSSREFS
Sequence in context: A020321 A177086 A254285 * A045198 A020417 A218848
KEYWORD
nonn,easy
AUTHOR
Joan Serra-Sagrista (jserra(AT)ccd.uab.es)
EXTENSIONS
a(10) corrected, a(11)-a(12) added by Ray Chandler, Jan 19 2016
STATUS
approved