negaLucas
Compute the nth negaLucas number.
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 negalucas = require( '@stdlib/math/base/special/negalucas' );
negalucas( n )
Computes the nth negaLucas number.
var v = negalucas( 0 );
// returns 2
v = negalucas( -1 );
// returns -1
v = negalucas( -2 );
// returns 3
v = negalucas( -3 );
// returns -4
v = negalucas( -76 );
// returns 7639424778862807
If n < -76, the function returns NaN, as larger negaLucas numbers cannot be safely represented in double-precision floating-point format.
var v = negalucas( -77 );
// returns NaN
If not provided a nonpositive integer value, the function returns NaN.
var v = negalucas( -3.14 );
// returns NaN
v = negalucas( 1 );
// returns NaN
If provided NaN, the function returns NaN.
var v = negalucas( NaN );
// returns NaN
Examples
var negalucas = require( '@stdlib/math/base/special/negalucas' );
var v;
var i;
for ( i = 0; i > -77; i-- ) {
v = negalucas( i );
console.log( v );
}
C APIs
Usage
#include "stdlib/math/base/special/negalucas.h"
stdlib_base_negalucas( n )
Computes the nth negaLucas number.
double out = stdlib_base_negalucas( 0 );
// returns 0
out = stdlib_base_negalucas( -1 );
// returns -1
The function accepts the following arguments:
- n:
[in] int32_tinput value.
double stdlib_base_negalucas( const int32_t n );
Examples
#include "stdlib/math/base/special/negalucas.h"
#include <stdio.h>
#include <stdint.h>
int main( void ) {
int32_t i;
double v;
for ( i = 0; i > -77; i-- ) {
v = stdlib_base_negalucas( i );
printf( "negalucas(%d) = %lf\n", i, v );
}
}