A008390 Crystal ball sequence for A_7 lattice.

1, 57, 869, 6637, 33111, 124223, 380731, 1004307, 2360501, 5064013, 10089705, 18912785, 33681595, 57426435, 94307855, 149907847, 231567369, 348773633, 513600589, 741206037, 1050388799, 1464209383

Offset

0,2

Links

T. D. Noe, Table of n, a(n) for n = 0..1000

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 crystal ball sequences

Index entries for linear recurrences with constant coefficients, signature (8,-28,56,-70,56,-28,8,-1).

Formula

a(n) = 143/210*n^7+143/60*n^6+451/60*n^5+77/6*n^4+937/60*n^3+707/60*n^2+363/70*n+1. - T. D. Noe, Apr 29 2007

G.f.: (1+x)*(1+48*x+393*x^2+832*x^3+393*x^4+48*x^5+x^6)/(1-x)^8. - Colin Barker, Mar 16 2012

Mathematica

LinearRecurrence[{8, -28, 56, -70, 56, -28, 8, -1}, {1, 57, 869, 6637, 33111, 124223, 380731, 1004307}, 30] (* Harvey P. Dale, Dec 16 2017 *)

Crossrefs

Sequence in context: A210149 A254783 A233370 * A231311 A008922 A332947

Adjacent sequences: A008387 A008388 A008389 * A008391 A008392 A008393

Keyword

nonn

Author

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

Status

approved