Even Fibonacci numbers
Problem 2
Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be:
1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...
By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even-valued terms.
Go to the thread for problem 2 in the forum.
Even(是偶数的意思……(─.─|||
f=[1,1,1]
i=2
ans=0
while f[i]+f[i-1]<4000000:
i=i+1
f.append(f[i-1]+f[i-2])
if (f[i]%2==0): ans=ans+f[i]
print sum(f)-1,f,ans