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A212975 Number of (w,x,y) with all terms in {0,...,n} and even range.

%I A212975 #14 Jun 18 2017 02:26:45
%S A212975 1,2,15,28,65,102,175,248,369,490,671,852,1105,1358,1695,2032,2465,
%T A212975 2898,3439,3980,4641,5302,6095,6888,7825,8762,9855,10948,12209,13470,
%U A212975 14911,16352,17985,19618,21455,23292,25345,27398,29679,31960
%N A212975 Number of (w,x,y) with all terms in {0,...,n} and even range.
%C A212975 a(n)+A212976(n) = (n+1)^3.
%C A212975 For a guide to related sequences, see A212959.
%H A212975 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (2,1,-4,1,2,-1).
%F A212975 a(n) = (n+1)*(2*n*(n+2)+3*(-1)^n+1)/4.
%F A212975 a(n) = 2*a(n-1)+a(n-2)-4*a(n-3)+a(n-4)+2*a(n-5)-a(n-6).
%F A212975 G.f.: f(x)/g(x), where f(x) = 1 + 10*x^2 + x^4 and g(x) = ((1-x)^4)*(1+x)^2.
%t A212975 t = Compile[{{n, _Integer}}, Module[{s = 0},
%t A212975 (Do[If[Mod[Max[w, x, y] - Min[w, x, y], 2] == 0,
%t A212975    s = s + 1],
%t A212975 {w, 0, n}, {x, 0, n}, {y, 0, n}]; s)]];
%t A212975 m = Map[t[#] &, Range[0, 60]]   (* A212975 *)
%Y A212975 Cf. A212959, A212976.
%K A212975 nonn,easy
%O A212975 0,2
%A A212975 _Clark Kimberling_, Jun 03 2012