#### Blue Java Program For Keith Number

If a Fibonacci sequence (in which each term in the sequence is the sum of the previous t terms) is formed, with is the first ‘t’ terms being the decimal digits of the number n, then n itself occurs as a term in the sequence.

For example,

14 is a Keith number

Because it generates the sequence:-

1, 4, 5, 9, 14

(1+4)=5, (5+9)=14, (9+14)=23………

Some keith numbers are: 14 ,19, 28 , 47 , 61, 75, 197….

import java.io.*;

import java.util.*;

class Keith

{

public static void main(String args[])

{

Scanner sc=new Scanner(System.in);

System.out.print(“Enter the number : “); //inputting the number

int n=sc.nextInt();

int copy=n;

String s=Integer.toString(n);

int d=s.length(); //finding the number of digits (d) in the number

int arr[]=new int[n]; //array for storing the terms of the series

for(int i=d-1; i>=0; i–)

{

arr[i]=copy%10; //storing the digits of the number in the array

copy=copy/10;

}

int i=d,sum=0;

while(sum<n) //finding the sum till it is less than the number

{

sum = 0;

for(int j=1; j<=d; j++) //loop for generating and adding the previous ‘d’ terms

{

sum=sum+arr[i-j];

}

arr[i]=sum; //storing the sum in the array

i++;

}

if(sum==n) //if sum is equal to the number, then it is a Keith number

System.out.println(“The number is a Keith Number”);

else

System.out.println(“The number is a not a Keith Number”);

}

}