According to Wikipedia A pronic number is a number which is the product of
two consecutive integers, that is, a number of the form n(n + 1). It is also called oblong number,
rectangular number or heteromecic number.
Examples : 0, 2, 6, 12, 20, 30, 42, 56, 72, 90,
110, 132, 156, 182, 210, 240, 272, 306, 342, 380, 420, 462, 506, 552 etc
Method I
// Java program to find Pronic Number
import java.io.*;
class PronicNumber
{
public
static void main(String args[]) throws IOException
{
int n,
i; // n for number and i for
loop
boolean
f=false; // f for flag, initialize
with false
InputStreamReader in = new InputStreamReader(System.in);
BufferedReader br = new BufferedReader(in);
System.out.print("Enter a number to find pronic or not : ");
n = Integer.parseInt(br.readLine());
for(i=1; i<=n; i++)
{
if(i*(i+1) == n)
{
f = true;
break;
}
}
//
Checking the pronic number
if(f ==
true)
System.out.println(n+" is a Pronic Number.");
else
System.out.println(n+" is not a Pronic Number.");
}
}
Sample Output:
Enter a number to find pronic or not : 110
110 is a Pronic Number.
Enter a number to find pronic or not : 272
272 is a Pronic Number.
Enter a number to find pronic or not : 6
6 is a Pronic Number.
Enter a number to find pronic or not : 35
35 is not a Pronic Number.
Method II
// Java program to find Pronic Number
import java.io.*;
class PronicNumberWithFunction
{
int n, i; // n instance variable for number
and i for loop
boolean
f=false; // f instance for flag,
initialize with false
boolean
pronic()throws IOException
{
InputStreamReader in = new InputStreamReader(System.in);
BufferedReader
br = new BufferedReader(in);
System.out.print("Enter a number to find pronic or not : ");
n =
Integer.parseInt(br.readLine());
for(i=1; i<=n; i++)
{
if(i*(i+1) == n)
{
f = true;
break;
}
}
return
f;
}
// Main
method start
public
static void main(String args[]) throws IOException
{
//
Checking the pronic number
boolean
f;
PronicNumberWithFunction ob = new PronicNumberWithFunction();
f =
ob.pronic();
if(f ==
true)
System.out.println("A number is a Pronic Number.");
else
System.out.println("The number is not a Pronic Number.");
}
}
Sample Output:
Enter a number to find pronic or not : 12
The number is a Pronic Number.
Enter a number to find pronic or not : 130
The number is not a Pronic Number.