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A035852
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Coordination sequence for A_26 lattice.
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0
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1, 702, 123552, 9746802, 438575202, 12873059082, 268708978512, 4237937201862, 52823066222862, 538709704223262, 4620645082106352, 34084184942296242, 220231986648034842, 1265712901796074842, 6554224549952044992
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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 (26, -325, 2600, -14950, 65780, -230230, 657800, -1562275, 3124550, -5311735, 7726160, -9657700, 10400600, -9657700, 7726160, -5311735, 3124550, -1562275, 657800, -230230, 65780, -14950, 2600, -325, 26, -1).
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FORMULA
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Sum_{d=1..26} C(27, d)*C(m/2-1, d-1)*C(26-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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