| public static pentagonalNumber ( integer $n ) : array | ||
| $n | integer | How many numbers in the sequence |
| Результат | array | Indexed from 1 |
public static function pentagonalNumber(int $n) : array
{
$pentagonal = [];
// Bad input; return empty list
if ($n <= 0) {
return $pentagonal;
}
// Standard case for pn: (3n² - n) / 2
for ($i = 1; $i <= $n; $i++) {
$pentagonal[$i] = (3 * $i ** 2 - $i) / 2;
}
return $pentagonal;
}