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Search: id:A035921
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| A035921 |
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Coordination sequence for diamond structure D^+_90. (Edges defined by l_1 norm = 1.) |
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1
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| 1, 16200, 43750800, 47297528280, 27425793987360, 9912269336940648, 2448015194902257840, 439668298578779894520, 60071753985937273120320, 6460749140008058788098440, 561838152794479347081022416
(list; graph; listen)
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OFFSET
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0,2
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REFERENCES
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J. Serra-Sagrista, Enumeration of lattice points in l_1 norm, Information Processing Letters, 76, no. 1-2 (2000), 39-44.
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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 (Abstract, pdf, ps).
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MAPLE
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f := proc(m) local k, t1; t1 := 2^(n-1)*binomial((n+2*m)/2-1, n-1); if m mod 2 = 0 then t1 := t1+add(2^k*binomial(n, k)*binomial(m-1, k-1), k=0..n); fi; t1; end; where n=90.
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CROSSREFS
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Sequence in context: A134120 A109566 A031843 this_sequence A109151 A068761 A043607
Adjacent sequences: A035918 A035919 A035920 this_sequence A035922 A035923 A035924
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KEYWORD
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nonn
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AUTHOR
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J. Serra-Sagrista (jserra(AT)ccd.uab.es) Recomputed by N. J. A. Sloane (njas(AT)research.att.com) Nov 27 1998.
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