A035716 Coordination sequence for 21-dimensional cubic lattice.

1, 42, 882, 12362, 130242, 1101450, 7796978, 47568618, 255582978, 1229718378, 5369283570, 21507034122, 79749022402, 275848947402, 895903147122, 2747597899690, 7996359740418, 22180063387818, 58861356563058, 149959897539018

Offset

0,2

Links

Seiichi Manyama, Table of n, a(n) for n = 0..10000

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

Adjacent sequences: A035713 A035714 A035715 * A035717 A035718 A035719

Keyword

nonn,easy

Author

Joan Serra-Sagrista (jserra(AT)ccd.uab.es)

Extensions

Recomputed by N. J. A. Sloane, Nov 25 1998

Status

approved