Question

Using Python:

The Fibonacci sequence is a famous series of numbers with the following rules:

The first number in the sequence is 0 -

The second number in the sequence is 1 -

The other numbers in the sequence are composed by adding up the two previous numbers in the sequence. We therefore have the following sequence: 1 st number: 0 2nd number: 1 3 rd number: 0 + 1 = 1 4 th number: 1+1 =2 5 th number: 2+1 = 3 6 th number: 3 + 2 = 5 7 th number: 5 + 3 = 8 and so on….

a. Write a program that takes a value n from the user and , using recursive function, display the first n Fibonacci numbers. (3pts)

b. Then, using List Comprehension, indicate which of the first n Fibonacci numbers are (2pts) : - odd numbers - multiples of 5

Example: How many Fibonacci numbers do you want ? 2 The first Fibonacci numbers are : [0, 1] From this list, the odd numbers are : [1] There is no multiples of 5 in this list How many Fibonacci numbers do you want ? 5 The first Fibonacci numbers are : [0, 1, 1, 2, 3] From this list, the odd numbers are : [1, 1, 3] There is no multiples of 5 in this list How many Fibonacci numbers do you want ? 11 The first Fibonacci numbers are: [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55] From this list, the odd numbers are : [1, 1, 3, 5, 13, 21, 55] From this list, the multiples of 5 are : [5, 55] Note that 0 is neither an odd number nor multiple of 5

Answer 1

Here is the completed code for this problem. Comments are included, go through it, learn how things work and let me know if you have any doubts or if you need anything to change. If you are satisfied with the solution, please rate the answer. Thanks

Note: Please maintain proper code spacing (indentation), just copy the code part and paste it in your compiler/IDE directly, no modifications required.

#code

#recursive method to find and return a list of first n fibonacci numbers
#here current and prev parameters are used for recursion. The calling
#program need not pass any values to these
def fibonacci(n,current=1, prev=0):
    #if n is invalid or reached 0, returning None (base condition)
    if n<=0:
        return None
    else:
        #creating a list containing prev element
        data=[prev]
        #finding remaining list of fibonacci numbers, passing one less value for n,
        #adding prev to current, passing old current as new prev
        remaining=fibonacci(n-1,current+prev,current)
        #if value of remaining is not None, appending the contents of remaining to
        #data list. Python lists have built in implementation for '+' and '+=' methods that
        #concatenates two lists
        if remaining is not None:
            data+=remaining
        #returning this list
        return data

#reading value for n
n=int(input("How many Fibonacci numbers do you want ? "))
#finding a list of n fibonacci numbers
numbers=fibonacci(n)
#using a list comprehension, finding a list of odd numbers from numbers list
odd=[i for i in numbers if i>0 and i%2!=0]
#using a list comprehension, finding a list of multiples of 5 from numbers list
multiplesOf5=[i for i in numbers if i>0 and i%5==0]

#printing numbers
print("The first {} Fibonacci numbers are :".format(n))
print(numbers)
#printing odd numbers if it is not empty, else printing proper messages
if len(odd)==0:
    print("There are no odd numbers in this list")
else:
    print("From this list, the odd numbers are :")
    print(odd)

#printing list of multiples of 5 if it is not empty, else printing proper messages
if len(multiplesOf5)==0:
    print("There are no multiples of 5 in this list")
else:
    print("From this list, the multiples of 5 are :")
    print(multiplesOf5)

#output

How many Fibonacci numbers do you want ? 10

The first 10 Fibonacci numbers are :

[0, 1, 1, 2, 3, 5, 8, 13, 21, 34]

From this list, the odd numbers are :

[1, 1, 3, 5, 13, 21]

From this list, the multiples of 5 are :

[5]