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A035716
Coordination sequence for 21-dimensional cubic lattice.
1
1, 42, 882, 12362, 130242, 1101450, 7796978, 47568618, 255582978, 1229718378, 5369283570, 21507034122, 79749022402, 275848947402, 895903147122, 2747597899690, 7996359740418, 22180063387818, 58861356563058, 149959897539018
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 (21, -210, 1330, -5985, 20349, -54264, 116280, -203490, 293930, -352716, 352716, -293930, 203490, -116280, 54264, -20349, 5985, -1330, 210, -21, 1).
FORMULA
G.f.: ((1+x)/(1-x))^21.
n*a(n) = 42*a(n-1) + (n-2)*a(n-2) for n > 1. - Seiichi Manyama, Aug 20 2018
MATHEMATICA
CoefficientList[Series[((1 + x)/(1 - x))^21, {x, 0, 30}], x] (* Wesley Ivan Hurt, Dec 02 2021 *)
CROSSREFS
Sequence in context: A030020 A090969 A010958 * A296011 A161663 A162179
KEYWORD
nonn,easy
AUTHOR
Joan Serra-Sagrista (jserra(AT)ccd.uab.es)
EXTENSIONS
Recomputed by N. J. A. Sloane, Nov 25 1998
STATUS
approved