Problem 25
The Fibonacci sequence is defined by the recurrence relation:
F1 = 1 F2 = 1
Fn = Fn−1 + Fn−2
Hence the first 12 terms will be:
F1 = 1
F2 = 1
F3 = 2
F4 = 3
F5 = 5
F6 = 8
F7 = 13
F8 = 21
F9 = 34
F10 = 55
F11 = 89
F12 = 144
The 12th term, F12, is the first term to contain three digits.
What is the first term in the Fibonacci sequence to contain 1000 digits?
# 第几个斐波那契数第一个拥有1000位数?
l = [1,1] i = 0 while True: if len(str(l[i+1])) == 1000: print(i+2) break l.append(l[i] + l[i+1]) i += 1结果:4782