Even Fibonacci numbers
Author: Eric Hodges
https://projecteuler.net/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.
Source code: prob002-eric256.pl
use v6; my $term = 1; my $last_term = 0; my $sum = 0; while ($term < 4000000) { ($last_term, $term) = ($term, $term + $last_term); $sum += $term unless $term % 2; } say $sum;