A035809 - OEIS

A035809

Coordination sequence for lattice D*_48 (with edges defined by l_1 norm = 1).

1, 96, 4608, 147488, 3542016, 68095200, 1091884544, 15023056032, 181095585792, 1943370847584, 18801236605440, 165673550159136, 1341056098444288, 10043368807877088, 70018291338395136, 456821317532555680

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OFFSET

0,2

COMMENTS

Starts to differ from A035743 at a(24). - R. J. Mathar, Oct 24 2008

LINKS

Table of n, a(n) for n=0..15.

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 (48, -1128, 17296, -194580, 1712304, -12271512, 73629072, -377348994, 1677106640, -6540715896, 22595200368, -69668534468, 192928249296, -482320623240, 1093260079344, -2254848913647, 4244421484512, -7309837001104, 11541847896480, -16735679449896, 22314239266528, -27385657281648, 30957699535776, -32247603683100, 30957699535776, -27385657281648, 22314239266528, -16735679449896, 11541847896480, -7309837001104, 4244421484512, -2254848913647, 1093260079344, -482320623240, 192928249296, -69668534468, 22595200368, -6540715896, 1677106640, -377348994, 73629072, -12271512, 1712304, -194580, 17296, -1128, 48, -1).

FORMULA

a(m) = (Sum_{k=0..n} 2^k*binomial(n, k)*binomial(m-1, k-1)) + 2^n*binomial((n+2*m)/2-1, n-1); with n=48.

CROSSREFS

Sequence in context: A268871 A017812 A035743 * A017759 A251159 A004392

Adjacent sequences: A035806 A035807 A035808 * A035810 A035811 A035812

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, J. Serra-Sagrista (jserra(AT)ccd.uab.es)

STATUS

approved