A158388 - OEIS

%I #26 Jan 03 2024 08:48:26

%S -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 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 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 -1 followed by infinitely many 1's.

%C Up to the sign of a(0), the same as the "all ones" sequence A000012. - _M. F. Hasler_, May 30 2020

%H <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (1).

%F G.f.: (2x-1)/(1-x). - _Philippe Deléham_, Mar 19 2009

%F a(n) = (-1)^A000007(n) = (-1)^[n=0], where [.] is the Iverson bracket. - _M. F. Hasler_, May 30 2020

%t PadRight[{-1},120,1] (* _Harvey P. Dale_, Apr 05 2023 *)

%o (PARI) a(n)=if(n,1,-1) \\ _Charles R Greathouse IV_, Jun 13 2013

%o (PARI) apply( {A158388(n)=1-!n*2}, [0..90]) \\ _M. F. Hasler_, May 30 2020

%Y Cf. A000012, A000007.

%K sign,mult,easy

%O 0,1

%A _Jaroslav Krizek_, Mar 17 2009