Algorithm of Fibonacci in php

fibonacci.php

<?php

function fibonacci(int $serie): array {
  $firstNro = 0;
  $secondNro = 1;
  $arraySequence = [0];

  for ($i=1; $i <= $serie; $i++) {
    $suma = $firstNro + $secondNro;

    $arraySequence[$i] = $suma;

    $firstNro = $secondNro;
    $secondNro = $suma;
  }

  return $arraySequence;
}

$result = fibonacci(10);

print_r($result);