<?php include("vendor/autoload.php"); define("MAX", 1000000); CodingTests\Prime::isPrime((3)); $primes = []; function is_prime(int $n) :bool{for($i=$n**.5|1;$i&&$n%$i--;);return!$i&&$n>1;} for($p= 1; $p < MAX; $p+=2) { if($p%1001 == 0) { echo $p."\n"; } if(CodingTests\Prime::isPrime($p)) { $primes[] = $p; } } echo "Precalculate done"; $longest = 0; for($start = 0; $start < sizeof($primes); $start++) { for($len = 1; $len <sizeof($primes)-$start; $len++) { //print_r(array_slice($primes, $start, $len)); $sum = array_sum(array_slice($primes, $start, $len)); if($sum > MAX) { continue 2; } if(in_array($sum, $primes) && $len > $longest) { echo "Found $len=>$sum \n"; $longest = $len; } } }