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 A016922 #56 Jul 08 2025 06:00:24
%S A016922 1,49,169,361,625,961,1369,1849,2401,3025,3721,4489,5329,6241,7225,
%T A016922 8281,9409,10609,11881,13225,14641,16129,17689,19321,21025,22801,
%U A016922 24649,26569,28561,30625,32761,34969,37249,39601,42025,44521,47089,49729,52441,55225
%N A016922 a(n) = (6*n+1)^2.
%C A016922 Except for 2, exponents e such that x^e-x+1 is reducible.
%H A016922 Vincenzo Librandi, <a href="/A016922/b016922.txt">Table of n, a(n) for n = 0..2000</a>
%H A016922 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1).
%F A016922 G.f.: ( 1+46*x+25*x^2 ) / (1-x)^3. - _R. J. Mathar_, Mar 10 2011
%F A016922 a(n) = A016921(n)^2 = A000290(A016921(n)). - _Wesley Ivan Hurt_, Dec 06 2013
%F A016922 a(n) = 24*A005449(n)+1. - _Jean-Bernard François_, Oct 12 2014
%F A016922 a(n) = 3*a(n-1)-3*a(n-2)+a(n-3). - _Wesley Ivan Hurt_, Oct 13 2014
%F A016922 Sum_{n>=0} 1/a(n) = A086727. - _Amiram Eldar_, Nov 16 2020
%p A016922 A016922:=n->(6*n+1)^2; seq(A016922(n), n=0..100); # _Wesley Ivan Hurt_, Dec 06 2013
%t A016922 Table[(6n+1)^2, {n,0,100}] (* or *)
%t A016922 CoefficientList[Series[(1 + 46*x + 25*x^2)/(1 - x)^3, {x, 0, 30}], x] (* _Wesley Ivan Hurt_, Oct 13 2014 *)
%t A016922 LinearRecurrence[{3,-3,1},{1,49,169},50] (* _Harvey P. Dale_, Feb 17 2023 *)
%o A016922 (Magma) [(6*n+1)^2: n in [0..60]]; // _Vincenzo Librandi_, May 04 2011
%o A016922 (PARI) a(n)=(6*n+1)^2 \\ _Charles R Greathouse IV_, Jun 17 2017
%Y A016922 Cf. A000290, A005449, A086727, A016778 (bisection), A016921.
%K A016922 nonn,easy
%O A016922 0,2
%A A016922 _N. J. A. Sloane_