A057428 Sign(-n): a(n) = 1 if -n > 0, = -1 if -n < 0, = 0 if n = 0.

0, -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

0,1

Links

Table of n, a(n) for n=0..83.

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

Formula

G.f.: A(x) = -x/(1-x).

a(n) = -A057427(n).

Series reversion of g.f. A(x) is A(A(x)). - Nikolaos Pantelidis, Apr 13 2022

Mathematica

Table[Sign[-n], {n, 0, 80}] (* Arkadiusz Wesolowski, Sep 16 2012 *)

Prog

(PARI) a(n) = sign(-n); \\ Michel Marcus, Apr 13 2022

Crossrefs

First differences of A001489.

Cf. A057427.

Sequence in context: A165471 A165481 A165573 * A165574 A165581 A165586

Adjacent sequences: A057425 A057426 A057427 * A057429 A057430 A057431

Keyword

easy,sign

Author

Henry Bottomley, Sep 05 2000

Status

approved