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 A212977 #16 Jan 05 2025 12:31:37
%S A212977 0,3,6,16,25,46,64,100,130,185,230,308,371,476,560,696,804,975,1110,
%T A212977 1320,1485,1738,1936,2236,2470,2821,3094,3500,3815,4280,4640,5168,
%U A212977 5576,6171,6630,7296,7809,8550,9120,9940,10570,11473,12166,13156
%N A212977 Number of (w,x,y) with all terms in {0,...,n} and n/2 < w+x+y <= n.
%C A212977 For a guide to related sequences, see A212959.
%H A212977 <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (1,3,-3,-3,3,1,-1).
%F A212977 a(n) = a(n-1)+3*a(n-2)-3*a(n-3)-3*a(n-4)+3*a(n-5)+a(n-6)-a(n-7).
%F A212977 G.f.: x*(3 + 3*x + x^2)/((1 + x)^3*(1 - x)^4).
%F A212977 a(n) = (14*n^3+75*n^2+109*n-3*((n^2+7*n+11)*(-1)^n-11))/96. - _Luce ETIENNE_, Mar 21 2014
%t A212977 t = Compile[{{n, _Integer}}, Module[{s = 0},
%t A212977 (Do[If[n/2 < w + x + y <= n, s = s + 1],
%t A212977 {w, 0, n}, {x, 0, n}, {y, 0, n}]; s)]];
%t A212977 m = Map[t[#] &, Range[0, 70]] (* A212977 *)
%Y A212977 Cf. A212959.
%K A212977 nonn,easy
%O A212977 0,2
%A A212977 _Clark Kimberling_, Jun 04 2012