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 A241890 #22 Jun 24 2025 13:07:47
%S A241890 24,25,28,33,40,49,60,73,88,105,124,145,168,193,220,249,280,313,348,
%T A241890 385,424,465,508,553,600,649,700,753,808,865,924,985,1048,1113,1180,
%U A241890 1249,1320,1393,1468,1545,1624,1705,1788,1873,1960,2049,2140,2233,2328,2425,2524
%N A241890 a(n) = n^2 + 24.
%H A241890 Vincenzo Librandi, <a href="/A241890/b241890.txt">Table of n, a(n) for n = 0..1000</a>
%H A241890 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1).
%F A241890 G.f.: (24 - 47*x + 25*x^2)/(1 - x)^3.
%F A241890 a(n) = a(-n) = 3*a(n-1) - 3*a(n-2) + a(n-3) = a(n-1) + 2*n - 1.
%F A241890 From _Amiram Eldar_, Nov 04 2020: (Start)
%F A241890 Sum_{n>=0} 1/a(n) = (1 + sqrt(24)*Pi*coth(sqrt(24)*Pi))/48.
%F A241890 Sum_{n>=0} (-1)^n/a(n) = (1 + sqrt(24)*Pi*cosech(sqrt(24)*Pi))/48. (End)
%F A241890 E.g.f.: exp(x)*(24 + x + x^2). - _Elmo R. Oliveira_, Nov 29 2024
%t A241890 Table[n^2 + 24, {n, 0, 60}]
%t A241890 LinearRecurrence[{3,-3,1},{24,25,28},60] (* _Harvey P. Dale_, Jun 24 2025 *)
%o A241890 (Magma) [n^2+24: n in [0..60]];
%o A241890 (PARI) a(n)=n^2+24 \\ _Charles R Greathouse IV_, Jun 17 2017
%Y A241890 Cf. similar sequences listed in A114962.
%K A241890 nonn,easy
%O A241890 0,1
%A A241890 _Vincenzo Librandi_, May 01 2014