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 A008420 #23 Jun 06 2018 14:37:04
%S A008420 1,20,200,1340,6800,28004,97880,299660,822560,2060980,4780008,
%T A008420 10377180,21278640,41517060,77548920,139380012,242080320,407782740,
%U A008420 668274440,1068305020,1669752016,2556801700,3842321560,5675620300
%N A008420 Coordination sequence for 10-dimensional cubic lattice.
%H A008420 Seiichi Manyama, <a href="/A008420/b008420.txt">Table of n, a(n) for n = 0..10000</a> (terms 0..1000 from T. D. Noe)
%H A008420 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 A008420 <a href="/index/Rec#order_10">Index entries for linear recurrences with constant coefficients</a>, signature (10, -45, 120, -210, 252, -210, 120, -45, 10, -1).
%F A008420 G.f.: ((1+x)/(1-x))^10.
%F A008420 n*a(n) = 20*a(n-1) + (n-2)*a(n-2) for n > 1. - _Seiichi Manyama_, Jun 06 2018
%t A008420 CoefficientList[Series[((1 + x)/(1 - x))^10, {x, 0, 30}], x] (* _Wesley Ivan Hurt_, Apr 18 2017 *)
%K A008420 nonn,easy
%O A008420 0,2
%A A008420 _N. J. A. Sloane_