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# Fibonacci Series in Python Using Range

Simple fibonacci series in python using range. In this program, we can execute the Fibonacci series in python using a given range by the users in python.

## Fibonacci Series Definition

The Fibonacci sequence is a set of numbers in which each subsequent number is equal to the sum of the two numbers before it. The sequence starts with 0 and 1 and goes on indefinitely: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, and so on. Xn+2= Xn+1 + Xn is a mathematical equation that can be used to define the Fibonacci sequence.

## Function Definition

A function is a piece of code that only executes when called. If a return statement is given, Python functions return a value. After a function has been declared, it can be invoked from anywhere.

## For Loop Definition in Python

When you have a block of code that you want to repeat a certain number of times, you use a for a loop. The for the statement in Python iterates through the members of a sequence, executing the block each time.

## Fibonacci Series in Python Using Range

``````import math
def isfunc(x):
s = int(math.sqrt(x))
return s*s == x
def fib(n):
return isfunc(5*n*n + 4) or isfunc(5*n*n - 4)
for i in range(5,13):
if (fib(i) == True):
print (i," Fibonacci Number")
else:
print (i,"Not Fibonacci Number ")``````

Output:

5  Fibonacci Number

6 Not Fibonacci Number

7 Not Fibonacci Number

8  Fibonacci Number

9 Not Fibonacci Number

10 Not Fibonacci Number

11 Not Fibonacci Number

12 Not Fibonacci Number

13  Fibonacci Number