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 A211786 #16 Sep 08 2022 08:46:02 %S A211786 1,12,40,96,187,324,514,768,1093,1500,1996,2592,3295,4116,5062,6144, %T A211786 7369,8748,10288,12000,13891,15972,18250,20736,23437,26364,29524, %U A211786 32928,36583,40500,44686,49152,53905,58956,64312,69984,75979,82308 %N A211786 n^3 + floor(n^3/2). %C A211786 Row 2 of the array A211785. %H A211786 Bruno Berselli, <a href="/A211786/b211786.txt">Table of n, a(n) for n = 1..1000</a> %H A211786 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (3, -2, -2, 3, -1). %F A211786 a(n) = 3*a(n-1)-2*a(n-2)-2*a(n-3)+3*a(n-4)-a(n-5). %F A211786 G.f.: x*(1+9*x+6*x^2+2*x^3)/((1+x)*(1-x)^4). [_Bruno Berselli_, May 06 2012] %F A211786 a(n) = floor(3*n^3/2) = (6*n^3+(-1)^n-1)/4. [_Bruno Berselli_, May 06 2012] %t A211786 f[n_, m_] := Sum[Floor[n^3/k], {k, 1, m}] %t A211786 t = Table[f[n, 2], {n, 1, 90}] %t A211786 FindLinearRecurrence[t] %t A211786 LinearRecurrence[{3, -2, -2, 3, -1},{1, 12, 40, 96, 187},38] (* _Ray Chandler_, Aug 02 2015 *) %o A211786 (Magma) [n^3+Floor(n^3/2): n in [1..38]]; // _Bruno Berselli_, May 06 2012 %Y A211786 Cf. A032766 (n+floor(n/2)), A032528 (n^2+floor(n^2/2)), A211701. %K A211786 nonn,easy %O A211786 1,2 %A A211786 _Clark Kimberling_, Apr 20 2012