A158388 -1 followed by infinitely many 1'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, 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, 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

Offset: 0

Author

Jaroslav Krizek, Mar 17 2009

Keywords

• sign
• mult
• easy

Comments

Up to the sign of a(0), the same as the "all ones" sequence A000012. - M. F. Hasler, May 30 2020

Links

• Index entries for linear recurrences with constant coefficients, signature (1).

Crossrefs

Cf. A000012, A000007.

Programs

Mathematica

PadRight[{-1},120,1] (* Harvey P. Dale, Apr 05 2023 *)

PARI

a(n)=if(n,1,-1) \\ Charles R Greathouse IV, Jun 13 2013

PARI

apply( {A158388(n)=1-!n*2}, [0..90]) \\ M. F. Hasler, May 30 2020

Formula

G.f.: (2x-1)/(1-x). - Philippe Deléham, Mar 19 2009

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