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 A026041 #18 Oct 18 2022 15:12:38
%S A026041 12,20,32,49,72,102,140,187,244,312,392,485,592,714,852,1007,1180,
%T A026041 1372,1584,1817,2072,2350,2652,2979,3332,3712,4120,4557,5024,5522,
%U A026041 6052,6615,7212,7844,8512,9217,9960,10742,11564,12427,13332,14280,15272,16309,17392,18522,19700,20927,22204,23532,24912,26345
%N A026041 a(n) = d(n)/2, where d = A026040.
%H A026041 Vincenzo Librandi, <a href="/A026041/b026041.txt">Table of n, a(n) for n = 4..1000</a>
%H A026041 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,-6,4,-1).
%F A026041 For n>4, a(n) = a(n-1)+A022856(n+2). - Levi R. Self (levi.r.self(AT)gmail.com), Aug 04 2007
%F A026041 G.f.: -x^4*(7*x^3-24*x^2+28*x-12)/(x-1)^4. - _Colin Barker_, Oct 07 2012
%F A026041 a(n) = n*(n^2-3*n+14)/6. - _Vincenzo Librandi_, Oct 17 2013
%t A026041 CoefficientList[Series[-(7 x^3 - 24 x^2 + 28 x - 12)/(x - 1)^4, {x, 0, 60}], x] (* _Vincenzo Librandi_, Oct 17 2013 *)
%o A026041 (Magma) [n*(n^2-3*n+14)/6: n in [4..60]]; // _Vincenzo Librandi_, Oct 17 2013
%o A026041 (PARI) a(n)=n*(n^2-3*n+14)/6 \\ _Charles R Greathouse IV_, Oct 18 2022
%K A026041 nonn,easy
%O A026041 4,1
%A A026041 _Clark Kimberling_