A008378 Coordination sequence for D_10 lattice.

1, 180, 6440, 94620, 802640, 4687108, 20924280, 76392940, 238753440, 659632980, 1649142216, 3796582460, 8156356080, 16522765220, 31822575640, 58659933324, 104054451520, 178420035060, 296839277160, 480696051420, 759737228432, 1174643272260, 1780196817080

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

R. Bacher, P. de la Harpe and B. Venkov, Séries de croissance et séries d'Ehrhart associées aux réseaux de racines, C. R. Acad. Sci. Paris, 325 (Series 1) (1997), 1137-1142.

J. H. Conway and N. J. A. Sloane, Low-Dimensional Lattices VII: Coordination Sequences, Proc. Royal Soc. London, A453 (1997), 2369-2389 (pdf).

Index entries for linear recurrences with constant coefficients, signature (10,-45,120,-210,252,-210,120,-45,10,-1).

Formula

G.f.: (x^10 +170*x^9 +4685*x^8 +38200*x^7 +124850*x^6 +183356*x^5 +124850*x^4 +38200*x^3 +4685*x^2 +170*x +1) / (x -1)^10. [Colin Barker, Nov 19 2012]

Maple

1352/945*n^9+1328/63*n^7+3416/45*n^5+13136/189*n^3+1268/105*n;

Mathematica

CoefficientList[Series[(x^10 + 170 x^9 + 4685 x^8 + 38200 x^7 + 124850 x^6 + 183356 x^5 + 124850 x^4 + 38200 x^3 + 4685 x^2 + 170 x + 1)/(x - 1)^10, {x, 0, 50}], x] (* Vincenzo Librandi, Oct 15 2013 *)
LinearRecurrence[{10, -45, 120, -210, 252, -210, 120, -45, 10, -1}, {1, 180, 6440, 94620, 802640, 4687108, 20924280, 76392940, 238753440, 659632980, 1649142216}, 40] (* Harvey P. Dale, Jun 22 2017 *)

Crossrefs

A row of array A103903.

Cf. A008379 (partial sums).

Sequence in context: A250146 A243465 A271673 * A214818 A287022 A217791

Adjacent sequences: A008375 A008376 A008377 * A008379 A008380 A008381

Keyword

nonn,easy

Author

N. J. A. Sloane and J. H. Conway

Extensions

More terms from Vincenzo Librandi, Oct 15 2013

Status

approved