fibonacci sequence formula code example
Example 1: fibonacci sequence python
# WARNING: this program assumes the
# fibonacci sequence starts at 1
def fib(num):
"""return the number at index `num` in the fibonacci sequence"""
if num <= 2:
return 1
return fib(num - 1) + fib(num - 2)
# method 2: use `for` loop
def fib2(num):
a, b = 1, 1
for _ in range(num - 1):
a, b = b, a + b
return a
print(fib(6)) # 8
print(fib2(6)) # same result, but much faster
Example 2: fibonacci sequence
0, 1, 1, 2, 3, 5, 8, 13, 21, 34, ...
Example 3: fibonacci sequence
def fibonacci(n):
if n <= 0:
return 0
elif n == 1:
return 1
else:
return fibonacci(n-1) + fibonacci(n-2)
Example 4: fibinachi
def fib(n):
lisp = []
for i in range(n):
if len(lisp) < 3:
if len(lisp) == 0:
lisp.append(0)
else:
lisp.append(1)
else:
lisp.append(lisp[len(lisp)-1]+lisp[len(lisp)-2])
return lisp