Learn to write a simple java program to verify if a given number is **pronic number** or not.

## 1. what is a pronic number

A pronic number is a number which is the product of two consecutive integers, that is, a number of the form **‘n x (n + 1)’**. They are also called **oblong numbers**, **heteromecic numbers**, or **rectangular numbers**.

For example, consider following example of number 6.

Given number is : 6

2 x 3 = 6 //6 is pronic number

The first few pronic numbers are: 0, 2, 6, 12, 20, 30, 42, 56, 72, 90, 110, 132, 156, 182, 210 etc.

## 2. Algorithm to determine pronic number

To find if a given number is pronic or not –

- Find the square root ‘K’ of given number.
- Multiply K with K+1. If number is equal tooriginal number, the number pronic number; else not.

## 3. Java Program to find pronic number

public class Main { public static void main(String[] args) { System.out.println("56 is pronic number " + isPronicNumber(56)); System.out.println("57 is pronic number " + isPronicNumber(57)); } static boolean isPronicNumber(int numberToCheck) { int sqrt = (int)(Math.sqrt(numberToCheck)); return sqrt * (sqrt + 1) == numberToCheck ? true : false; } }

Program output.

56 is pronic number true 57 is pronic number false

Happy Learning !!

Ref : Wikipedia

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