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 A022281 #24 Aug 23 2017 23:39:27
%S A022281 0,12,47,105,186,290,417,567,740,936,1155,1397,1662,1950,2261,2595,
%T A022281 2952,3332,3735,4161,4610,5082,5577,6095,6636,7200,7787,8397,9030,
%U A022281 9686,10365,11067,11792,12540,13311
%N A022281 a(n) = n*(23*n + 1)/2.
%H A022281 G. C. Greubel, <a href="/A022281/b022281.txt">Table of n, a(n) for n = 0..5000</a>
%H A022281 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1)
%F A022281 a(n) = 23*n + a(n-1) - 11 for n>0, a(0)=0. - _Vincenzo Librandi_, Aug 04 2010
%F A022281 G.f.: x*(12 + 11*x)/(1 - x)^3 . - _R. J. Mathar_, Aug 04 2016
%F A022281 a(n) = A000217(12*n) - A000217(11*n). - _Bruno Berselli_, Oct 13 2016
%F A022281 E.g.f.: (x/2)*(23*x + 24)*exp(x). - _G. C. Greubel_, Aug 23 2017
%t A022281 Table[n (23 n + 1)/2, {n, 0, 40}] (* or *) LinearRecurrence[{3, -3, 1}, {0, 12, 47}, 40] (* _Harvey P. Dale_, Aug 16 2016 *)
%o A022281 (PARI) a(n)=n*(23*n+1)/2 \\ _Charles R Greathouse IV_, Jun 16 2017
%Y A022281 Cf. similar sequences listed in A022289.
%K A022281 nonn,easy
%O A022281 0,2
%A A022281 _N. J. A. Sloane_