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 A167573 #18 Jun 10 2025 23:33:35
%S A167573 23,83,183,323,503,723,983,1283,1623,2003,2423,2883,3383,3923,4503,
%T A167573 5123,5783,6483,7223,8003,8823,9683,10583,11523,12503,13523,14583,
%U A167573 15683,16823,18003,19223,20483,21783,23123,24503,25923,27383,28883,30423,32003,33623,35283
%N A167573 a(n) = 20*n^2 + 3.
%H A167573 G. C. Greubel, <a href="/A167573/b167573.txt">Table of n, a(n) for n = 1..1000</a>
%H A167573 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1).
%F A167573 a(n) = 20*n^2 + 3.
%F A167573 G.f.: z*(3*z^2 + 14*z + 23)/(1-z)^3. [Corrected by _Elmo R. Oliveira_, May 31 2025]
%F A167573 a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n > 3. - _G. C. Greubel_, Jun 16 2016
%F A167573 E.g.f.: -3 + (3 + 20*x + 20*x^2)*exp(x). - _Elmo R. Oliveira_, May 31 2025
%t A167573 Table[20*n^2 + 3, {n, 1, 100}] (* or *) LinearRecurrence[{3,-3,1},{23, 83, 183}, 100] (* _G. C. Greubel_, Jun 16 2016 *)
%o A167573 (PARI) a(n)=20*n^2+3 \\ _Charles R Greathouse IV_, Jun 17 2017
%Y A167573 Equals the third row of the ED3 array A167572.
%K A167573 easy,nonn
%O A167573 1,1
%A A167573 _Johannes W. Meijer_, Nov 10 2009