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A035715
Coordination sequence for 20-dimensional cubic lattice.
1
1, 40, 800, 10680, 107200, 864008, 5831520, 33940120, 174074240, 800061160, 3339504032, 12798246520, 45443741760, 150656183240, 469398016480, 1382296736088, 3866465104640, 10317238542760, 26364054632480, 64734486343480
OFFSET
0,2
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 (20, -190, 1140, -4845, 15504, -38760, 77520, -125970, 167960, -184756, 167960, -125970, 77520, -38760, 15504, -4845, 1140, -190, 20, -1).
FORMULA
G.f.: ((1+x)/(1-x))^20.
n*a(n) = 40*a(n-1) + (n-2)*a(n-2) for n > 1. - Seiichi Manyama, Aug 20 2018
MATHEMATICA
CoefficientList[Series[((1+x)/(1-x))^20, {x, 0, 30}], x] (* Harvey P. Dale, Mar 26 2016 *)
CROSSREFS
Sequence in context: A010956 A006240 A126928 * A035609 A161653 A162176
KEYWORD
nonn,easy
AUTHOR
Joan Serra-Sagrista (jserra(AT)ccd.uab.es)
EXTENSIONS
Recomputed by N. J. A. Sloane, Nov 25 1998
STATUS
approved