A035896 Coordination sequence for diamond structure D^+_40. (Edges defined by l_1 norm = 1.)

1, 0, 3200, 0, 1708800, 0, 366366080, 0, 42340840960, 0, 3070951360128, 0, 153524473002240, 0, 5639746542798720, 0, 159505036253752320, 0, 3599066875202445440, 0, 66639047830192168704, 21990232555520

Offset

0,3

Links

Ray Chandler, Table of n, a(n) for n = 0..1000

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.

Index entries for linear recurrences with constant coefficients, signature (0, 40, 0, -780, 0, 9880, 0, -91390, 0, 658008, 0, -3838380, 0, 18643560, 0, -76904685, 0, 273438880, 0, -847660528, 0, 2311801440, 0, -5586853480, 0, 12033222880, 0, -23206929840, 0, 40225345056, 0, -62852101650, 0, 88732378800, 0, -113380261800, 0, 131282408400, 0, -137846528820, 0, 131282408400, 0, -113380261800, 0, 88732378800, 0, -62852101650, 0, 40225345056, 0, -23206929840, 0, 12033222880, 0, -5586853480, 0, 2311801440, 0, -847660528, 0, 273438880, 0, -76904685, 0, 18643560, 0, -3838380, 0, 658008, 0, -91390, 0, 9880, 0, -780, 0, 40, 0, -1).

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=40.

Crossrefs

Sequence in context: A235781 A235562 A269114 * A224646 A231203 A035777

Adjacent sequences: A035893 A035894 A035895 * A035897 A035898 A035899

Keyword

nonn

Author

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

Extensions

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

Status

approved