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 A022280 #29 Nov 09 2024 18:44:09
%S A022280 0,11,45,102,182,285,411,560,732,927,1145,1386,1650,1937,2247,2580,
%T A022280 2936,3315,3717,4142,4590,5061,5555,6072,6612,7175,7761,8370,9002,
%U A022280 9657,10335,11036,11760,12507,13277
%N A022280 a(n) = n*(23*n - 1)/2.
%H A022280 G. C. Greubel, <a href="/A022280/b022280.txt">Table of n, a(n) for n = 0..5000</a>
%H A022280 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1).
%F A022280 a(n) = 23*n + a(n-1) - 12 for n>0, a(0)=0. - _Vincenzo Librandi_, Aug 04 2010
%F A022280 From _Colin Barker_, Jun 05 2012: (Start)
%F A022280 G.f.: x*(11 + 12*x)/(1 - x)^3.
%F A022280 a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3). (End)
%F A022280 a(n) = A000217(12*n-1) - A000217(11*n-1). - _Bruno Berselli_, Oct 14 2016
%F A022280 E.g.f.: (x/2)*(23*x + 22)*exp(x). - _G. C. Greubel_, Aug 23 2017
%t A022280 Table[n (23 n - 1)/2, {n, 0, 40}] (* _Bruno Berselli_, Oct 14 2016 *)
%t A022280 LinearRecurrence[{3,-3,1},{0,11,45},40] (* _Harvey P. Dale_, Nov 09 2024 *)
%o A022280 (PARI) a(n)=n*(23*n-1)/2 \\ _Charles R Greathouse IV_, Jun 16 2017
%Y A022280 Cf. A000217, A022281.
%Y A022280 Cf. similar sequences listed in A022288.
%K A022280 nonn,easy
%O A022280 0,2
%A A022280 _N. J. A. Sloane_