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A035897
Coordination sequence for diamond structure D^+_42. (Edges defined by l_1 norm = 1.)
1
1, 0, 3528, 0, 2076816, 0, 490681688, 0, 62456027424, 0, 4985149915368, 0, 273998113272240, 0, 11053262513080440, 0, 342841481215636032, 0, 8471578904288191496, 0, 171504713146698879696, 2199023255552
OFFSET
0,3
LINKS
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.
Index entries for linear recurrences with constant coefficients, signature (0, 42, 0, -861, 0, 11480, 0, -111930, 0, 850668, 0, -5245786, 0, 26978328, 0, -118030185, 0, 445891810, 0, -1471442973, 0, 4280561376, 0, -11058116888, 0, 25518731280, 0, -52860229080, 0, 98672427616, 0, -166509721602, 0, 254661927156, 0, -353697121050, 0, 446775310800, 0, -513791607420, 0, 538257874440, 0, -513791607420, 0, 446775310800, 0, -353697121050, 0, 254661927156, 0, -166509721602, 0, 98672427616, 0, -52860229080, 0, 25518731280, 0, -11058116888, 0, 4280561376, 0, -1471442973, 0, 445891810, 0, -118030185, 0, 26978328, 0, -5245786, 0, 850668, 0, -111930, 0, 11480, 0, -861, 0, 42, 0, -1).
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=42.
CROSSREFS
Sequence in context: A187726 A267125 A241240 * A064256 A232555 A330841
KEYWORD
nonn
AUTHOR
Joan Serra-Sagrista (jserra(AT)ccd.uab.es)
EXTENSIONS
Recomputed by N. J. A. Sloane, Nov 27 1998
STATUS
approved