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

%I #15 Sep 05 2023 14:01:39

%S 1,0,9248,0,14260416,0,8807231072,0,2920221095296,0,604286975278752,0,

%T 85587416923429440,0,8833008614958340320,0,695102146176221154048,0,

%U 43172047917347942629664,0,2174464783015655477758912,0,90787245914896872516139872,0,3199582752316460419118637184,0

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

%H Georg Fischer, <a href="/A035910/b035910.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=68.

%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