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A035890
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Coordination sequence for diamond structure D^+_28. (Edges defined by l_1 norm = 1.)
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1
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1, 0, 1568, 0, 410816, 0, 43381856, 0, 2485013888, 0, 90102925472, 0, 2275791199808, 0, 42760561395424, 3758096384, 627153507629824, 544923975680, 7450881715909408, 27028229193728, 73852826419374016
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OFFSET
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0,3
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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 (0, 28, 0, -378, 0, 3276, 0, -20475, 0, 98280, 0, -376740, 0, 1184040, 0, -3108105, 0, 6906900, 0, -13123110, 0, 21474180, 0, -30421755, 0, 37442160, 0, -40116600, 0, 37442160, 0, -30421755, 0, 21474180, 0, -13123110, 0, 6906900, 0, -3108105, 0, 1184040, 0, -376740, 0, 98280, 0, -20475, 0, 3276, 0, -378, 0, 28, 0, -1).
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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=28.
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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Joan Serra-Sagrista (jserra(AT)ccd.uab.es)
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EXTENSIONS
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STATUS
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approved
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