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 A154360 #29 Sep 08 2022 08:45:40
%S A154360 -180,70,320,570,820,1070,1320,1570,1820,2070,2320,2570,2820,3070,
%T A154360 3320,3570,3820,4070,4320,4570,4820,5070,5320,5570,5820,6070,6320,
%U A154360 6570,6820,7070,7320,7570,7820,8070,8320,8570,8820,9070,9320,9570,9820,10070,10320
%N A154360 a(n) = 250*n - 180.
%C A154360 The identity (1250*n^2 - 1800*n + 649)^2 - (25*n^2 - 36*n + 13)*(250*n - 180)^2 = 1 can be written as A154358(n)^2 - A154355(n)*a(n)^2 = 1. See also the third comment in A154357.
%H A154360 Vincenzo Librandi, <a href="/A154360/b154360.txt">Table of n, a(n) for n = 0..10000</a>
%H A154360 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1).
%F A154360 G.f.: -10*(18 - 43*x)/(1-x)^2. - _Bruno Berselli_, Dec 13 2011
%F A154360 a(n) = 2*a(n-1) - a(n-2). - _Vincenzo Librandi_, Feb 21 2012
%F A154360 E.g.f.: 10*(-18 + 25*x)*exp(x). - _G. C. Greubel_, Sep 15 2016
%t A154360 LinearRecurrence[{2, -1}, {-180, 70}, 50] (* _Vincenzo Librandi_, Feb 21 2012 *)
%o A154360 (PARI) for(n=0, 50, print1(250n - 180", ")); \\ _Vincenzo Librandi_, Feb 21 2012
%o A154360 (Magma) [250*n-180: n in [0..50]]; // _Bruno Berselli_, Sep 15 2016
%Y A154360 Cf. A154361, A154359, A154358, A154357, A154355.
%K A154360 sign,easy
%O A154360 0,1
%A A154360 _Vincenzo Librandi_, Jan 08 2009
%E A154360 Offset changed and Librandi's comment rewritten by _Bruno Berselli_, Dec 13 2011