# npm

## @stdlib/math-iter-sequences-squared-triangular 0.0.7 • Public • Published

# iterSquaredTriangularSeq

Create an iterator which generates a sequence of squared triangular numbers.

The squared triangular numbers are the integer sequence

starting at the 0th squared triangular number.

Triangular numbers are given by the following explicit formulas

where the last formula corresponds to a binomial coefficient, representing the number of distinct pairs that can be selected from n+1 items.

The nth squared triangular number is the nth triangular number squared.

## Installation

npm install @stdlib/math-iter-sequences-squared-triangular

## Usage

var iterSquaredTriangularSeq = require( '@stdlib/math-iter-sequences-squared-triangular' );

#### iterSquaredTriangularSeq( [options] )

Returns an iterator which generates a sequence of squared triangular numbers.

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

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

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

v = it.next().value;
// returns 9

v = it.next().value;
// returns 36

v = it.next().value;
// returns 100

// ...

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: 11585.

By default, the function returns a finite iterator to avoid exceeding the maximum safe double-precision floating-point integer. To adjust the number of iterations, set the iter option.

var opts = {
'iter': 2
};
var it = iterSquaredTriangularSeq( opts );
// returns <Object>

var 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 iterSquaredTriangularSeq = require( '@stdlib/math-iter-sequences-squared-triangular' );

// Create an iterator:
var opts = {
'iter': 100
};
var it = iterSquaredTriangularSeq( opts );

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

## Notice

This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.

#### Community ### Install

npm i @stdlib/math-iter-sequences-squared-triangular

stdlib.io

20

0.0.7