Fibonacci numbers in PowerShell

function Get-Fibonacci ($n) {
 if ($n -le 1) {
 return 1
 }
 return (Get-Fibonacci ($n - 1)) + (Get-Fibonacci ($n - 2))
}
$output = ""
foreach ($i in 0..15) {
 $output += ("{0}, " -f (Get-Fibonacci $i))
}
echo "$output..."