A035889 Coordination sequence for diamond structure D^+_26. (Edges defined by l_1 norm = 1.)

1, 0, 1352, 0, 305552, 0, 27866072, 0, 1381251872, 0, 43450388072, 0, 955155127472, 33554432, 15676941638904, 11777605632, 201710366471744, 796951314432, 2112804738688904, 24705490747392, 18563618015178704

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, 26, 0, -325, 0, 2600, 0, -14950, 0, 65780, 0, -230230, 0, 657800, 0, -1562275, 0, 3124550, 0, -5311735, 0, 7726160, 0, -9657700, 0, 10400600, 0, -9657700, 0, 7726160, 0, -5311735, 0, 3124550, 0, -1562275, 0, 657800, 0, -230230, 0, 65780, 0, -14950, 0, 2600, 0, -325, 0, 26, 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=26.

Crossrefs

Sequence in context: A154375 A243132 A349070 * A192320 A237310 A035763

Adjacent sequences: A035886 A035887 A035888 * A035890 A035891 A035892

Keyword

nonn

Author

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

Extensions

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

Status

approved