This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A008386 #26 Apr 08 2018 16:20:33
%S A008386 1,31,271,1281,4251,11253,25493,51563,95693,166003,272755,428605,
%T A008386 648855,951705,1358505,1894007,2586617,3468647,4576567,5951257,
%U A008386 7638259,9688029,12156189,15103779,18597509
%N A008386 Crystal ball sequence for A_5 lattice.
%C A008386 Partial sums of A008385.
%H A008386 T. D. Noe, <a href="/A008386/b008386.txt">Table of n, a(n) for n = 0..1000</a>
%H A008386 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 A008386 <a href="/index/Cor#crystal_ball">Index entries for crystal ball sequences</a>
%H A008386 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (6,-15,20,-15,6,-1).
%F A008386 a(n) = (2*n+1)*(63*n^4+126*n^3+217*n^2+154*n+60)/60. - _T. D. Noe_, Apr 29 2007
%F A008386 G.f.: (1+x)*(1+24*x+76*x^2+24*x^3+x^4)/(1-x)^6. - _Colin Barker_, Mar 16 2012
%t A008386 LinearRecurrence[{6,-15,20,-15,6,-1},{1,31,271,1281,4251,11253},30] (* _Harvey P. Dale_, Apr 08 2018 *)
%K A008386 nonn,easy
%O A008386 0,2
%A A008386 _N. J. A. Sloane_ and _J. H. Conway_