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 A017090 #31 Apr 24 2023 02:54:19
%S A017090 4,100,324,676,1156,1764,2500,3364,4356,5476,6724,8100,9604,11236,
%T A017090 12996,14884,16900,19044,21316,23716,26244,28900,31684,34596,37636,
%U A017090 40804,44100,47524,51076,54756,58564,62500,66564,70756,75076,79524,84100,88804,93636,98596
%N A017090 a(n) = (8*n + 2)^2.
%H A017090 Vincenzo Librandi, <a href="/A017090/b017090.txt">Table of n, a(n) for n = 0..10000</a>
%H A017090 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1).
%F A017090 G.f.: -4*(1 + 22*x + 9*x^2)/(x-1)^3. - _R. J. Mathar_, Jul 14 2016
%F A017090 From _Amiram Eldar_, Apr 24 2023: (Start)
%F A017090 a(n) = A017089(n)^2.
%F A017090 a(n) = 2^2*A016814(n).
%F A017090 Sum_{n>=0} 1/a(n) = Pi^2/64 + G/8, where G is Catalan's constant (A006752). (End)
%t A017090 Table[(8*n + 2)^2, {n, 0, 40}] (* _Amiram Eldar_, Apr 24 2023 *)
%o A017090 (Magma) [(8*n+2)^2: n in [0..35]]; // _Vincenzo Librandi_, Jul 12 2011
%o A017090 (PARI) a(n)=(8*n+2)^2 \\ _Charles R Greathouse IV_, Jun 17 2017
%Y A017090 Cf. A006752, A016814, A017089 (8n+2), A000290 (n^2).
%K A017090 nonn,easy
%O A017090 0,1
%A A017090 _N. J. A. Sloane_