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 A200252 #16 Feb 19 2018 08:26:12 %S A200252 5,12,26,45,75,112,164,225,305,396,510,637,791,960,1160,1377,1629, %T A200252 1900,2210,2541,2915,3312,3756,4225,4745,5292,5894,6525,7215,7936, %U A200252 8720,9537,10421,11340,12330,13357,14459,15600,16820,18081,19425,20812,22286,23805 %N A200252 Number of 0..n arrays x(0..2) of 3 elements with each no smaller than the sum of its previous elements modulo (n+1). %C A200252 Row 3 of A200251. %C A200252 a(n) = A199771(n+1). - _Reinhard Zumkeller_, Nov 23 2011 %H A200252 R. H. Hardin, <a href="/A200252/b200252.txt">Table of n, a(n) for n = 1..210</a> %H A200252 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (2,1,-4,1,2,-1). %F A200252 a(n) = 2*a(n-1) + a(n-2) - 4*a(n-3) + a(n-4) + 2*a(n-5) - a(n-6). %F A200252 From _Colin Barker_, Feb 19 2018: (Start) %F A200252 G.f.: x*(5 + 2*x - 3*x^2 + x^3 + 2*x^4 - x^5) / ((1 - x)^4*(1 + x)^2). %F A200252 a(n) = (n^3 + 5*n^2 + 8*n + 4) / 4 for n even. %F A200252 a(n) = (n^3 + 5*n^2 + 9*n + 5) / 4 for n odd. %F A200252 (End) %e A200252 Some solutions for n=6: %e A200252 2 0 0 3 3 1 4 0 1 3 0 3 0 2 1 3 %e A200252 6 5 3 6 3 1 5 2 4 6 6 5 0 5 2 4 %e A200252 2 6 6 2 6 4 4 2 6 5 6 5 6 5 4 0 %K A200252 nonn,easy %O A200252 1,1 %A A200252 _R. H. Hardin_, Nov 15 2011