import math def isPerfectSquare(x): s = int(math.sqrt(x)) return s*s == x def isFibonacci(n): # n is Fibonacci if one of 5*n*n + 4 or 5*n*n - 4 or both # is a perfect square return isPerfectSquare(5*n*n + 4) or isPerfectSquare(5*n*n - 4) for i in range(1, 11): if (isFibonacci(i) == True): print(i, "is a Fibonacci Number") else: print(i, "is a not Fibonacci Number ")