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 A145923 #38 Mar 24 2024 02:31:28
%S A145923 9,33,65,105,153,209,273,345,425,513,609,713,825,945,1073,1209,1353,
%T A145923 1505,1665,1833,2009,2193,2385,2585,2793,3009,3233,3465,3705,3953,
%U A145923 4209,4473,4745,5025,5313,5609,5913,6225,6545,6873,7209,7553,7905,8265,8633,9009,9393
%N A145923 Second bisection of A061041: a(n) = A061041(2n+1) = (2*n+1)*(2*n+9).
%H A145923 Paolo Xausa, <a href="/A145923/b145923.txt">Table of n, a(n) for n = 0..10000</a>
%H A145923 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1).
%F A145923 a(n) = (2*n+1)*(2*n+9).
%F A145923 G.f.: (9 + 6*x - 7*x^2)/(1-x)^3 . - _R. J. Mathar_, Oct 23 2016
%F A145923 E.g.f.: (9 + 24*x + 4*x^2)*exp(x). - _G. C. Greubel_, Mar 23 2024
%t A145923 A145923[n_]:=4n^2+20n+9; Array[A145923,100,0] (* or *)
%t A145923 LinearRecurrence[{3,-3,1},{9,33,65},100] (* _Paolo Xausa_, Dec 05 2023 *)
%t A145923 (2*Range[0,60] +5)^2 -16 (* _G. C. Greubel_, Mar 23 2024 *)
%o A145923 (PARI) a(n)=4*n^2+20*n+9 \\ _Charles R Greathouse IV_, Jun 17 2017
%o A145923 (Magma) [(2*n+5)^2-16: n in [0..60]]; // _G. C. Greubel_, Mar 23 2024
%o A145923 (SageMath) [(2*n+5)^2-16 for n in range(61)] # _G. C. Greubel_, Mar 23 2024
%Y A145923 Cf. A061041.
%K A145923 nonn,easy,less
%O A145923 0,1
%A A145923 _Paul Curtz_, Oct 25 2008
%E A145923 More terms from _Jinyuan Wang_, Mar 23 2020