A035926 Coordination sequence for diamond structure D^+_100. (Edges defined by l_1 norm = 1.)

1, 0, 20000, 0, 66680000, 0, 88977788000, 0, 63669939056000, 0, 28388261970800800, 0, 8645481416595304000, 0, 1913769409906455052000, 0, 322081772124335598304000, 0, 42639787126552298702388000, 0, 4560880160205473732557707200, 0, 402747462617285816887874972000, 0, 29887395794995795375534035536000, 0

Offset: 0

Author

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

Keywords

• nonn

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.

Programs

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=100.

Extensions

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

Zeroes inserted by Georg Fischer, Jul 26 2020