Determining whether a number is a Fibonacci number

Question

I need to to write a Java code that checks whether the user inputed number is in the Fibonacci sequence.

I have no issue writing the Fibonacci sequence to output, b

Answer 1

//Program begins


public class isANumberFibonacci {

    public static int fibonacci(int seriesLength) {
        if (seriesLength == 1 || seriesLength == 2) {
            return 1;
        } else {
            return fibonacci(seriesLength - 1) + fibonacci(seriesLength - 2);
        }
    }

    public static void main(String args[]) {
        int number = 4101;
        int i = 1;
        while (i > 0) {
            int fibnumber = fibonacci(i);
            if (fibnumber != number) {
                if (fibnumber > number) {
                    System.out.println("Not fib");
                    break;
                } else {
                    i++;
                }
            } else {
                System.out.println("The number is fibonacci");
                break;
            }
        }
    }
}

//Program ends