Fibonacci numbers in PowerShell

Example for versions Windows PowerShell 5.0 
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..."