A035911 Coordination sequence for diamond structure D^+_70. (Edges defined by l_1 norm = 1.)

1, 0, 9800, 0, 16013200, 0, 10479036120, 0, 3681129969440, 0, 806898799084392, 0, 121032811973584560, 0, 13225339591553573880, 0, 1101592116648629874240, 0, 72393605649421626732680, 0, 3856647616141475449361872, 0, 170239941030636357079306520, 0, 6340353831737951399852254560, 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=70.

Crossrefs

Sequence in context: A010092 A023339 A145209 * A069333 A222814 A156735

Adjacent sequences: A035908 A035909 A035910 * A035912 A035913 A035914

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