A035916 Coordination sequence for diamond structure D^+_80. (Edges defined by l_1 norm = 1.)

1, 0, 12800, 0, 27315200, 0, 23338104320, 0, 10698844067840, 0, 3058431999744512, 0, 597778600580572160, 0, 85027230683021319680, 0, 9208060526880831549440, 0, 785696146272773983470080, 0, 54264336460274894557740032, 0, 3100237607076259583597381120, 0, 149174495875885415147284367360, 0

Offset

0,3

Links

Georg Fischer, Table of n, a(n) for n = 0..200

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

Joan Serra-Sagrista, Enumeration of lattice points in l_1 norm, Inf. Proc. Lett. 76 (1-2) (2000) 39-44.

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=80.

Crossrefs

Sequence in context: A209091 A207133 A157509 * A243050 A246809 A204490

Adjacent sequences: A035913 A035914 A035915 * A035917 A035918 A035919

Keyword

nonn

Author

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

Extensions

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

Zeroes inserted by Georg Fischer, Jul 26 2020

Status

approved