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A035856
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Coordination sequence for A_30 lattice.
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0
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1, 930, 216690, 22583810, 1338036570, 51479517042, 1400792169890, 28618505434770, 458896797950430, 5976672906978410, 64971574193515962, 602758415976923850, 4860664625733355250, 34599738140887685850
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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 (30, -435, 4060, -27405, 142506, -593775, 2035800, -5852925, 14307150, -30045015, 54627300, -86493225, 119759850, -145422675, 155117520, -145422675, 119759850, -86493225, 54627300, -30045015, 14307150, -5852925, 2035800, -593775, 142506, -27405, 4060, -435, 30, -1).
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FORMULA
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Sum_{d=1..30} C(31, d)*C(m/2-1, d-1)*C(30-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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