A035910 Coordination sequence for diamond structure D^+_68. (Edges defined by l_1 norm = 1.)

1, 0, 9248, 0, 14260416, 0, 8807231072, 0, 2920221095296, 0, 604286975278752, 0, 85587416923429440, 0, 8833008614958340320, 0, 695102146176221154048, 0, 43172047917347942629664, 0, 2174464783015655477758912, 0, 90787245914896872516139872, 0, 3199582752316460419118637184, 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=68.

Crossrefs

Sequence in context: A236512 A031848 A184211 * A202466 A013815 A013900

Adjacent sequences: A035907 A035908 A035909 * A035911 A035912 A035913

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