In this article, we will understand how to find even sum of Fibonacci series till number N. A Fibonacci series is sequence of numbers formed by the sum of its two previous integers. An even Fibonacci series is all the even numbers of the Fibonacci series.
Below is a demonstration of the same −
Fibonacci series generates the subsequent number by adding two previous numbers. Fibonacci series starts from two numbers − F0 & F1. The initial values of F0 & F1 can be taken 0, 1 or 1, 1 respectively.
Fn = Fn-1 + Fn-2
Hence, a Fibonacci series can look like this −
F8 = 0 1 1 2 3 5 8 13
or, this,
F8 = 1 1 2 3 5 8 13 21
Input
Suppose our input is −
The input : 15
Output
The desired output would be −
The fibonacci series till 15 terms:
Algorithm
Step 1 - START Step 2 - Declare values namely Step 3 - Read the required values from the user/ define the values Step 4 - Use a for loop to iterate through the integers from 1 to N and assign the sum of consequent two numbers as the current Fibonacci number Step 5- Display the result Step 6- Stop
Example 1
Here, the input is being entered by the user based on a prompt. You can try this example live in ourcoding ground tool .
import java.util.Scanner; public class Main { public static void main(String[] args) { int my_input , term_1, term_2, term_3; term_1 = 0; term_2 = 1; System.out.println("Required packages have been imported"); Scanner my_scanner = new Scanner(System.in); System.out.println("A reader object has been defined "); System.out.print("Enter the number : "); my_input = my_scanner.nextInt(); System.out.println("The fibonacci series till " + my_input + " terms:"); for (int i = 1; i <= my_input; ++i) { System.out.print(term_1 + " "); term_3 = term_1 + term_2; term_1 = term_2; term_2 = term_3; } } }
Output
Required packages have been imported A reader object has been defined Enter the number : 15 The fibonacci series till 15 terms: 0 1 1 2 3 5 8 13 21 34 55 89 144 233 377
Example 2
Here, the integer has been previously defined, and its value is accessed and displayed on the console.
public class Main { public static void main(String[] args) { int my_input , term_1, term_2, term_3; my_input = 15; term_1 = 0; term_2 = 1; System.out.println("The number are defined as " +my_input ); System.out.println("The fibonacci series till " + my_input + " terms:"); for (int i = 1; i <= my_input; ++i) { System.out.print(term_1 + " "); term_3 = term_1 + term_2; term_1 = term_2; term_2 = term_3; } } }
Output
The number are defined as 15 The fibonacci series till 15 terms: 0 1 1 2 3 5 8 13 21 34 55 89 144 233 377