A035909 Coordination sequence for diamond structure D^+_66. (Edges defined by l_1 norm = 1.)

1, 0, 8712, 0, 12655632, 0, 7363888664, 0, 2300684695584, 0, 448681205484072, 0, 59904484213281840, 0, 5829554227763981880, 0, 432708304259607621696, 0, 25358927904615986491976, 0, 1205707495877530248973392, 0, 47541429981663923354785368, 0, 1583107940352344774704064608, 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=66.

Crossrefs

Sequence in context: A237874 A252646 A170796 * A031877 A222815 A233679

Adjacent sequences: A035906 A035907 A035908 * A035910 A035911 A035912

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