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 A010022 #36 Jul 08 2025 01:28:04
%S A010022 1,42,162,362,642,1002,1442,1962,2562,3242,4002,4842,5762,6762,7842,
%T A010022 9002,10242,11562,12962,14442,16002,17642,19362,21162,23042,25002,
%U A010022 27042,29162,31362,33642,36002,38442,40962,43562,46242,49002,51842,54762,57762,60842
%N A010022 a(0) = 1, a(n) = 40*n^2 + 2 for n>0.
%C A010022 First bisection of A005901. - _Bruno Berselli_, Feb 07 2012
%H A010022 Bruno Berselli, <a href="/A010022/b010022.txt">Table of n, a(n) for n = 0..1000</a>
%H A010022 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1).
%F A010022 G.f.: (1+x)*(1+38*x+x^2)/(1-x)^3; a(n) = A008253(4n). - _Bruno Berselli_, Feb 07 2012
%F A010022 E.g.f.: (x*(x+1)*40+2)*e^x-1. - _Gopinath A. R._, Feb 14 2012
%F A010022 Sum_{n>=0} 1/a(n) = 3/4 + sqrt(5)/40*Pi*coth(Pi*sqrt(5)/10) = 1.03983104279172.. - _R. J. Mathar_, May 07 2024
%F A010022 a(n) = 2*A158493(n), n>0. - _R. J. Mathar_, May 07 2024
%F A010022 a(n) = A195317(n)+A195317(n+1) = 2+10*A016742(n), n>0. - _R. J. Mathar_, May 07 2024
%t A010022 Join[{1}, 40 Range[39]^2 + 2] (* _Bruno Berselli_, Feb 07 2012 *)
%t A010022 Join[{1}, LinearRecurrence[{3, -3, 1}, {42, 162, 362}, 50]] (* _Vincenzo Librandi_, Aug 03 2015 *)
%o A010022 (Magma) [1] cat [40*n^2+2: n in [1..50]]; // _Vincenzo Librandi_, Aug 03 2015
%Y A010022 Cf. A206399.
%K A010022 nonn,easy
%O A010022 0,2
%A A010022 _N. J. A. Sloane_