Fibonacci

Compute the nth Fibonacci number.

The Fibonacci numbers are the integer sequence

0 comma 1 comma 1 comma 2 comma 3 comma 5 comma 8 comma 13 comma 21 comma 34 comma 55 comma 89 comma 144 comma ellipsis

The sequence is defined by the recurrence relation

upper F Subscript n Baseline equals upper F Subscript n minus 1 Baseline plus upper F Subscript n minus 2

with seed values F_0 = 0 and F_1 = 1.

Usage

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

fibonacci( n )

Computes the nth Fibonacci number.

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

v = fibonacci( 1 );
// returns 1

v = fibonacci( 2 );
// returns 1

v = fibonacci( 3 );
// returns 2

v = fibonacci( 78 );
// returns 8944394323791464

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

var v = fibonacci( 79 );
// returns NaN

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

var v = fibonacci( 3.14 );
// returns NaN

v = fibonacci( -1 );
// returns NaN

If provided NaN, the function returns NaN.

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

Examples

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

var v;
var i;

for ( i = 0; i < 79; i++ ) {
    v = fibonacci( i );
    console.log( v );
}