Sum of Even Fibonacci Sequence

By starting Fibonacci 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.

Excellent problem. My second take at Euler’s Project. Although it is the second easiest (possibly) problem in the website, my bragging right that I solved this problem in less than 10 minutes remains.

def fib(max)
n1, n2, n = 1, 2, 0
arr = [n1, n2]
while n < max
n = n1 + n2
n1, n2 = n2, n
arr << n
end
arr_sum = arr[0..-2].reject {|e| e % 2 != 0}.reduce(:+)
end
fib(4000000)

Without looking at wikipedia, Fibonacci number is an accumulation of numbers consisted of the sum of the previous two numbers. If a Fibonacci sequence starts with 0 and 1, then the sequence goes 0, 1, (0+1), (1+(0+1)),((0+1)+(1+(0+1))), and so on. They seem to appear everywhere, from hurricanes to galaxies to pineapples.


What other Fibonacci patterns do you recognize are around you?

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