A pronic number is a number which is the product of two consecutive integers, that is, a number of the form n(n + 1). The first few pronic numbers are: 0, 2, 6, 12, 20, 30, 42, 56, 72, 90, 110, 132, 156, 182, 210, 240, 272, 306, 342, 380, 420, 462 … etc.
import java.util.*;
class pronic
{//class pronic opens
public static void main(String[]args)
{//main method opens
Scanner sc=new Scanner(System.in);
System.out.println("Enter a no");
int n=sc.nextInt();//variable n to accept the no
int sq=(int)Math.sqrt(n);//variable sq to store the square root of the no
int p=sq*(sq+1);//variable p stores the product of the square root with the next number of the square root
if(p==n)
System.out.println("It is pronic no");
else
System.out.println("It is not a pronic no");
}//main method closes
}//class closes
