triangular-numbers

Functions to work with triangular numbers:

isTriangular

import isTriangular from 'triangular-numbers/isTriangular'

console.log(isTriangular(3))
// > true

console.log(isTriangular(5))
// > false

getNthTriangularNumber

import getNthTriangularNumber from 'triangular-numbers/getNthTriangularNumber'

console.log(getNthTriangularNumber(1))
// > 1
console.log(getNthTriangularNumber(2))
// > 3
console.log(getNthTriangularNumber(3))
// > 6
console.log(getNthTriangularNumber(4))
// > 10

getTriangularRootIndex

import getTriangularRootIndex from 'triangular-numbers/getTriangularRootIndex'

console.log(getTriangularRootIndex(10))
// > 4
console.log(getTriangularRootIndex(11))
// > 4
console.log(getTriangularRootIndex(5))
// > 2
console.log(getTriangularRootIndex(4))
// > 2
console.log(getTriangularRootIndex(3))
// > 2
console.log(getTriangularRootIndex(2))
// > 1

Installation

yarn add triangular-numbers

License

MIT