iterTribonacciSeq

Create an iterator which generates a tribonacci sequence.

The Tribonacci numbers are the integer sequence

$$0, 0, 1, 1, 2, 4, 7, 13, 24, 44, 81, 149, 274, \ldots$$

The sequence is defined by the recurrence relation

$$F_n = F_{n-1} + F_{n-2} + F_{n-3}$$

with seed values F_0 = 0, F_1 = 0, and F_2 = 1.

Usage

var iterTribonacciSeq = require( '@stdlib/math/iter/sequences/tribonacci' );

iterTribonacciSeq( [options] )

Returns an iterator which generates a Tribonacci sequence.

var it = iterTribonacciSeq();
// returns <Object>

var v = it.next().value;
// returns 0

v = it.next().value;
// returns 0

v = it.next().value;
// returns 1

// ...

The returned iterator protocol-compliant object has the following properties:

• next: function which returns an iterator protocol-compliant object containing the next iterated value (if one exists) assigned to a value property and a done property having a boolean value indicating whether the iterator is finished.
• return: function which closes an iterator and returns a single (optional) argument in an iterator protocol-compliant object.

The function supports the following options:

• iter: number of iterations. Default: 64.

The returned iterator can only generate the first 64 Tribonacci numbers, as larger Tribonacci numbers cannot be safely represented in double-precision floating-point format. By default, the function returns an iterator which generates all 64 numbers. To limit the number of iterations, set the iter option.

var opts = {
    'iter': 3
};
var it = iterTribonacciSeq( opts );
// returns <Object>

var v = it.next().value;
// returns 0

v = it.next().value;
// returns 0

v = it.next().value;
// returns 1

var bool = it.next().done;
// returns true

Notes

• If an environment supports Symbol.iterator, the returned iterator is iterable.

Examples

var iterTribonacciSeq = require( '@stdlib/math/iter/sequences/tribonacci' );

// Create an iterator:
var it = iterTribonacciSeq();

// Perform manual iteration...
var v;
while ( true ) {
    v = it.next();
    if ( v.done ) {
        break;
    }
    console.log( v.value );
}

---

See Also

• @stdlib/math/base/special/tribonacci: compute the nth Tribonacci number.
• @stdlib/math/base/special/fibonacci: compute the nth Fibonacci number.
• @stdlib/math/iter/sequences/lucas: create an iterator which generates a Lucas sequence.