A035912 Coordination sequence for diamond structure D^+_72. (Edges defined by l_1 norm = 1.)

1, 0, 10368, 0, 17922816, 0, 12407366016, 0, 4610216314368, 0, 1068744800817792, 0, 169506887987474688, 0, 19580193687475702656, 0, 1723599538143585831936, 0, 119669709626799156403328, 0, 6733021714697626592585472, 0, 313769325989254807329936768, 0, 12331923156069951694058082816, 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=72.

Crossrefs

Sequence in context: A031803 A234907 A180460 * A226599 A305332 A271766

Adjacent sequences: A035909 A035910 A035911 * A035913 A035914 A035915

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