How do you check whether a given number n is a Fibonacci number or not?

Answer 1

In a Fibonacci sequence, sum of two successive terms gives the third term....

here is the Fibonacci sequence:

0,1,1,2,3,5,8,13,21,34,55,89,144........

General formula to generate a Fibonacci sequence is """Fn= Fn-1 + Fn-2"""

To check whether a number is Fibonacci or not follow the following steps:

1) Get the number as input from user.

2) Fix the first two numbers of sequence as 0 and 1.

3) put a sentinel loop with upper limit being the input number.

4)in the body of loop generate the next number in sequence in each iteration and continue swapping the values as follows:

a=0

b=1

next=a+b

while (next< input)

a=b

b=next

next=a+b wend

5) lastly when program exits the loop compare the last number of sequence with the input number

if they are equal then number is Fibonacci otherwise not.

otherwise the last term of sequence will be less than the input number.