List Manipulation — Question 12
Back to all questionsQuestion 10
Write a program that reads the n to display nth term of Fibonacci series.
The Fibonacci sequence works as follows:
- element 0 has the value 0
- element 1 has the value 1
- every element after that has the value of the sum of the two preceding elements
The beginning of the sequence looks like:
0, 1, 1, 2, 3, 5, 8, 13, 21, 34, ...
The program prompts for element and prints out the value of that element of the Fibonacci sequence.
Thus:
- input 7, produces 13
- input 9, produces 34
Hints:
A Don't try to just type out the entire list. It gets big very fast. Element 25 is 75205. Element 100 is 354224848179261915075. So keep upper limit of n to 20.
Solution
n = int(input("Enter n: "))
if (n > 20):
print("n should be less than or equal to 20")
else :
a = 0
b = 1
c = a + b
for i in range(3, n + 1):
a = b
b = c
c = a + b
print(n, "term of Fibonacci series =", c)Output
Enter n: 7
7 term of Fibonacci series = 13
=====================================
Enter n: 9
9 term of Fibonacci series = 34
=====================================
Enter n: 25
n should be less than or equal to 20
n
=
int
(
input
(
"Enter n: "
))
if
(
n
>
20
):
print
(
"n should be less than or equal to 20"
)
else
:
a
=
0
b
=
1
c
=
a
+
b
for
i
in
range
(
3
,
n
+
1
):
a
=
b
b
=
c
c
=
a
+
b
print
(
n
,
"term of Fibonacci series ="
,
c
)
Output
Enter n: 7
7 term of Fibonacci series = 13
=====================================
Enter n: 9
9 term of Fibonacci series = 34
=====================================
Enter n: 25
n should be less than or equal to 20