# negaFibonacci

Compute the nth negaFibonacci number.

The negaFibonacci numbers are the integer sequence

The sequence is defined by the recurrence relation

which yields

with seed values F_0 = 0 and F_{-1} = 1.

## Usage

var negafibonacci = require( '@stdlib/math/base/special/negafibonacci' );


#### negafibonacci( n )

Computes the nth negaFibonacci number.

var v = negafibonacci( 0 );
// returns 0

v = negafibonacci( -1 );
// returns 1

v = negafibonacci( -2 );
// returns -1

v = negafibonacci( -3 );
// returns 2

v = negafibonacci( -78 );
// returns -8944394323791464


If n < -78, the function returns NaN, as larger negaFibonacci numbers cannot be safely represented in double-precision floating-point format.

var v = negafibonacci( -79 );
// returns NaN


If not provided a nonpositive integer value, the function returns NaN.

var v = negafibonacci( -3.14 );
// returns NaN

v = negafibonacci( 1 );
// returns NaN


If provided NaN, the function returns NaN.

var v = negafibonacci( NaN );
// returns NaN


## Examples

var negafibonacci = require( '@stdlib/math/base/special/negafibonacci' );

var v;
var i;

for ( i = 0; i > -79; i-- ) {
v = negafibonacci( i );
console.log( v );
}