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Coordination sequence for 9-dimensional cubic lattice.
5

%I #28 Nov 11 2024 00:20:28

%S 1,18,162,978,4482,16722,53154,148626,374274,864146,1854882,3742290,

%T 7159170,13079250,22952610,38878482,63821826,101880594,158611106,

%U 241419474,360027522,527022162,758497698,1074801042,1501390338

%N Coordination sequence for 9-dimensional cubic lattice.

%H Seiichi Manyama, <a href="/A008418/b008418.txt">Table of n, a(n) for n = 0..10000</a> (terms 0..1000 from T. D. Noe)

%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 <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (9, -36, 84, -126, 126, -84, 36, -9, 1).

%F G.f.: ((1+x)/(1-x))^9.

%F n*a(n) = 18*a(n-1) + (n-2)*a(n-2) for n > 1. - _Seiichi Manyama_, Jun 06 2018

%t CoefficientList[Series[((1 + x)/(1 - x))^9, {x, 0, 30}], x] (* _Wesley Ivan Hurt_, Feb 04 2017 *)

%t LinearRecurrence[{9,-36,84,-126,126,-84,36,-9,1},{1,18,162,978,4482,16722,53154,148626,374274,864146},30] (* _Harvey P. Dale_, Aug 01 2024 *)

%K nonn,easy,changed

%O 0,2

%A _N. J. A. Sloane_