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A035885 Coordination sequence for diamond structure D^+_18. (Edges defined by l_1 norm = 1.) 0
1, 0, 648, 0, 70416, 0, 3116952, 0, 76117536, 131072, 1205253288, 22413312, 13740702000, 784465920, 121013567928, 13231325184, 863382367296, 141764198400, 5162116908744, 1105760747520 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

REFERENCES

J. Serra-Sagrista, Enumeration of lattice points in l_1 norm, Information Processing Letters, 76, no. 1-2 (2000), 39-44.

LINKS

Table of n, a(n) for n=0..19.

J. H. Conway and N. J. A. Sloane, Low-Dimensional Lattices VII: Coordination Sequences, Proc. Royal Soc. London, A453 (1997), 2369-2389 (pdf).

MAPLE

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=18.

CROSSREFS

Sequence in context: A046020 A108821 A345702 * A114827 A334896 A271639

Adjacent sequences:  A035882 A035883 A035884 * A035886 A035887 A035888

KEYWORD

nonn

AUTHOR

Joan Serra-Sagrista (jserra(AT)ccd.uab.es)

EXTENSIONS

Recomputed by N. J. A. Sloane, Nov 27 1998

STATUS

approved

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Last modified October 22 01:48 EDT 2021. Contains 348160 sequences. (Running on oeis4.)