negaLucas

Compute the nth negaLucas number in single-precision floating-point format.

The negaLucas numbers are the integer sequence

The sequence is defined by the recurrence relation

which yields

with seed values L_0 = 2 and L_{-1} = -1.

Usage

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

negalucasf( n )

Computes the nth negaLucas number in single-precision floating-point format.

var v = negalucasf( 0 );
// returns 2

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

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

v = negalucasf( -3 );
// returns -4

v = negalucasf( -34 );
// returns 12752043

If n < -34, the function returns NaN, as larger negaLucas numbers cannot be safely represented in single-precision floating-point format.

var v = negalucasf( -35 );
// returns NaN

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

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

v = negalucasf( 1 );
// returns NaN

If provided NaN, the function returns NaN.

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

Examples

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

var v;
var i;

for ( i = 0; i > -35; i-- ) {
    v = negalucasf( i );
    console.log( v );
}

C APIs

Usage

#include "stdlib/math/base/special/negalucasf.h"

stdlib_base_negalucasf( n )

Computes the nth negaLucas number in single-precision floating-point format.

float out = stdlib_base_negalucasf( 0 );
// returns 0.0f

out = stdlib_base_negalucasf( -1 );
// returns -1.0f

The function accepts the following arguments:

n: [in] int32_t input value.

float stdlib_base_negalucasf( const int32_t n );

Examples

#include "stdlib/math/base/special/negalucasf.h"
#include <stdio.h>
#include <stdint.h>

int main( void ) {
    int32_t i;
    float v;

    for ( i = 0; i > -35; i-- ) {
        v = stdlib_base_negalucasf( i );
        printf( "negalucasf(%d) = %f\n", i, v );
    }
}