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 A213486 #10 Feb 20 2024 11:18:20
%S A213486 0,3,12,27,48,78,120,174,240,321,420,537,672,828,1008,1212,1440,1695,
%T A213486 1980,2295,2640,3018,3432,3882,4368,4893,5460,6069,6720,7416,8160,
%U A213486 8952,9792,10683,11628,12627,13680,14790,15960,17190,18480,19833
%N A213486 Number of (w,x,y) with all terms in {0,...,n} and |w-x|+|x-y|+|y-w| > w+x+y.
%C A213486 Every term is divisible by 3.
%C A213486 For a guide to related sequences, see A212959.
%H A213486 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (4,-7,8,-7,4,-1).
%F A213486 a(n) = 4*a(n-1)-7*a(n-2)+8*a(n-3)-7*a(n-4)+4*a(n-5)-a(n-6).
%F A213486 G.f.: 3*x/((1 - x)^4 (1 + x^2)).
%F A213486 a(n) = (n+1)^3 - A213487(n).
%t A213486 t = Compile[{{n, _Integer}}, Module[{s = 0}, (Do[If[w + x + y < Abs[w - x] + Abs[x - y] + Abs[y - w], s = s + 1], {w, 0, n}, {x, 0, n}, {y, 0, n}]; s)]];
%t A213486 m = Map[t[#] &, Range[0, 60]] (* A213486 *)
%Y A213486 Cf. A212959, A213487.
%K A213486 nonn,easy
%O A213486 0,2
%A A213486 _Clark Kimberling_, Jun 13 2012