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 A258721 #15 Sep 08 2022 08:46:12
%S A258721 29,105,229,401,621,889,1205,1569,1981,2441,2949,3505,4109,4761,5461,
%T A258721 6209,7005,7849,8741,9681,10669,11705,12789,13921,15101,16329,17605,
%U A258721 18929,20301,21721,23189,24705,26269,27881,29541,31249,33005,34809,36661,38561,40509
%N A258721 a(n) = 24*n^2 + 52*n + 29.
%C A258721 First differences of A079588.
%C A258721 6*a(n) - 5 is a square. Therefore, this is the quadrisection of the sequence which lists the numbers m such that 6*m-5 is a square (without 1): 1, 5, 9, 21, 29, 49, 61, 89, 105, 141, 161, 205, 229, ... . [_Bruno Berselli_, Jun 08 2015]
%H A258721 Reinhard Zumkeller, <a href="/A258721/b258721.txt">Table of n, a(n) for n = 0..10000</a>
%H A258721 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1).
%F A258721 G.f.: (29 + 18*x + x^2)/(1 - x)^3.
%t A258721 Table[24 n^2 + 52 n + 29, {n, 0, 50}] (* _Bruno Berselli_, Jun 08 2015 *)
%o A258721 (Haskell)
%o A258721 a258721 n = 4 * n * (6 * n + 13) + 29
%o A258721 (PARI) vector(50, n, n--; 24*n^2+52*n+29) \\ _Bruno Berselli_, Jun 08 2015
%o A258721 (Sage) [24*n^2+52*n+29 for n in (0..50)] # _Bruno Berselli_, Jun 08 2015
%o A258721 (Magma) [24*n^2+52*n+29: n in (0..50)] // _Bruno Berselli_, Jun 08 2015
%o A258721 (Maxima) makelist(24*n^2+52*n+29, n, 0, 50); /* _Bruno Berselli_, Jun 08 2015 */
%Y A258721 Cf. A079588.
%K A258721 nonn,easy
%O A258721 0,1
%A A258721 _Reinhard Zumkeller_, Jun 08 2015