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A035849
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Coordination sequence for A_23 lattice.
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0
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1, 552, 76452, 4756952, 169447302, 3956576472, 66087441092, 839584669992, 8489857618992, 70764981877592, 499828461729852, 3059000328006312, 16519884821277962, 79920498285116712, 350767245201478812
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OFFSET
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0,2
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LINKS
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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 (23, -253, 1771, -8855, 33649, -100947, 245157, -490314, 817190, -1144066, 1352078, -1352078, 1144066, -817190, 490314, -245157, 100947, -33649, 8855, -1771, 253, -23, 1).
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FORMULA
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Sum_{d=1..23} C(24, d)*C(m/2-1, d-1)*C(23-d+m/2, m/2), where norm m is always even.
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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Joan Serra-Sagrista (jserra(AT)ccd.uab.es)
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STATUS
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approved
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