A035920 - OEIS

A035920

Coordination sequence for diamond structure D^+_88. (Edges defined by l_1 norm = 1.)

%I #16 Sep 05 2023 14:06:18

%S 1,0,15488,0,39990016,0,41333677440,0,22916557452800,0,

%T 7919942966638208,0,1870534029816486144,0,321315959969540069248,0,

%U 41994780120899506334720,0,4321124706193758340042880,0,359578487180206655473139456,0,24728329402573005235848884608,0,1430744078752131145758438498816,0

%N Coordination sequence for diamond structure D^+_88. (Edges defined by l_1 norm = 1.)

%H Georg Fischer, <a href="/A035920/b035920.txt">Table of n, a(n) for n = 0..200</a>

%H J. H. Conway and N. J. A. Sloane, Low-Dimensional Lattices VII: Coordination Sequences, Proc. Royal Soc. London, A453 (1997), 2369-2389 (<a href="http://neilsloane.com/doc/Me220.pdf">pdf</a>).

%H Joan Serra-Sagrista, <a href="http://dx.doi.org/10.1016/S0020-0190(00)00119-8">Enumeration of lattice points in l_1 norm</a>, Inf. Proc. Lett. 76 (1-2) (2000) 39-44.

%p 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=88.

%K nonn

%O 0,3

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

%E Recomputed by _N. J. A. Sloane_, Nov 27 1998

%E Zeroes inserted by _Georg Fischer_, Jul 26 2020