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 A158388 #26 Jan 03 2024 08:48:26
%S A158388 -1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
%T A158388 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
%U A158388 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1
%N A158388 -1 followed by infinitely many 1's.
%C A158388 Up to the sign of a(0), the same as the "all ones" sequence A000012. - _M. F. Hasler_, May 30 2020
%H A158388 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (1).
%F A158388 G.f.: (2x-1)/(1-x). - _Philippe Deléham_, Mar 19 2009
%F A158388 a(n) = (-1)^A000007(n) = (-1)^[n=0], where [.] is the Iverson bracket. - _M. F. Hasler_, May 30 2020
%t A158388 PadRight[{-1},120,1] (* _Harvey P. Dale_, Apr 05 2023 *)
%o A158388 (PARI) a(n)=if(n,1,-1) \\ _Charles R Greathouse IV_, Jun 13 2013
%o A158388 (PARI) apply( {A158388(n)=1-!n*2}, [0..90]) \\ _M. F. Hasler_, May 30 2020
%Y A158388 Cf. A000012, A000007.
%K A158388 sign,mult,easy
%O A158388 0,1
%A A158388 _Jaroslav Krizek_, Mar 17 2009