%I #22 Dec 16 2017 15:15:56

%S 1,57,869,6637,33111,124223,380731,1004307,2360501,5064013,10089705,

%T 18912785,33681595,57426435,94307855,149907847,231567369,348773633,

%U 513600589,741206037,1050388799,1464209383

%N Crystal ball sequence for A_7 lattice.

%H T. D. Noe, <a href="/A008390/b008390.txt">Table of n, a(n) for n = 0..1000</a>

%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/Cor#crystal_ball">Index entries for crystal ball sequences</a>

%H <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (8,-28,56,-70,56,-28,8,-1).

%F 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

%F 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

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

%K nonn

%O 0,2

%A _N. J. A. Sloane_ and _J. H. Conway_