September 2017 Update

Task/Pernicious-numbers/PowerShell/pernicious-numbers-2.psh

@@ -0,0 +1,44 @@
+function Select-PerniciousNumber
+{
+    [CmdletBinding()]
+    [OutputType([int])]
+    Param
+    (
+        [Parameter(Mandatory=$true,
+                   ValueFromPipeline=$true,
+                   ValueFromPipelineByPropertyName=$true,
+                   Position=0)]
+        $InputObject
+    )
+
+    Begin
+    {
+        function Test-Prime ([int]$n)
+        {
+            $n = [Math]::Abs($n)
+
+            if ($n -eq 0 -or $n -eq 1) {return $false}
+
+            for ($m = 2; $m -le [Math]::Sqrt($n); $m++)
+            {
+                if (($n % $m) -eq 0) {return $false}
+            }
+
+            return $true
+        }
+
+        [scriptblock]$popCount = {(([Convert]::ToString($this, 2)).ToCharArray() | Where-Object {$_ -eq '1'}).Count}
+    }
+    Process
+    {
+        foreach ($object in $InputObject)
+        {
+            $object | Add-Member -MemberType ScriptProperty -Name PopCount -Value $popCount -Force -PassThru | ForEach-Object {
+                if (Test-Prime $_.PopCount)
+                {
+                    $_
+                }
+            }
+        }
+    }
+}

Task/Pernicious-numbers/PowerShell/pernicious-numbers-3.psh

@@ -0,0 +1,9 @@
+$start, $end = 0, 999999
+$range1 = $start..$end | Select-PerniciousNumber | Select-Object -First 25
+
+"First {0} pernicious numbers:`n{1}`n" -f $range1.Count, ($range1 -join ", ")
+
+$start, $end = 888888877, 888888888
+$range2 = $start..$end | Select-PerniciousNumber
+
+"Pernicious numbers between {0} and {1}:`n{2}`n" -f $start, $end, ($range2 -join ", ")