# Project Euler Problem 2: Even Fibonacci Numbers¶

The source code for this problem can be found here.

## Problem Statement¶

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:

$$1, 2, 3, 5, 8, 13, 21, 34, 55, 89, \dots$$

By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even-valued terms.

## Solution Discussion¶

Simply iterate over the Fibonacci numbers up to four million and sum all the even ones.

## Solution Implementation¶

from itertools import takewhile

from lib.numbertheory import is_even
from lib.sequence import Fibonaccis

def solve():
""" Compute the answer to Project Euler's problem #2 """
upper_bound = 4000000
numbers = [fib_i for fib_i in takewhile(lambda x: x <= upper_bound, Fibonaccis()) if is_even(fib_i)]

solutions.problem2.solve()