My solution for https://ironscripter.us/a-powershell-cryptogram/

gistfile1.txt

$crypto = @"
P k T r 2 s z 2 * c F -
r a z 7 G u D 4 w 6 U #
g c t K 3 E @ B t 1 a Y
Q P i c % 7 0 5 Z v A e
W 6 j e P R f p m I ) H
y ^ L o o w C n b J d O
S i 9 M b e r # ) i e U
* f 2 Z 6 M S h 7 V u D
5 a ( h s v 8 e l 1 o W
Z O 7 l p K y J l D z $
- j I @ t T 2 3 R a i k
q = F & w B 6 c % H l y
"@
[string]$crypto=$crypto -replace '\s',''
$x=1;$y=12;$i=-1
[string]$message=do { 
            $i+=$x   
            $crypto[$i]
            $i+=$y
            $crypto[$i]                                 
}until($i-gt$crypto.Length)
($message -replace'\s','')

This was the loop I created to discover the params;

[string]$crypto=$crypto -replace '\s',''
$x=1;$max=12
do{ $y=1
  do{ $i=-1
      [string]$message=do { 
                            $i+=$x
                            $crypto[$i]
                            $i+=$y
                            $crypto[$i]
                                                   
      }until($i-gt$crypto.Length)
      "x=$x, y=$y"
      ($message -replace'\s','')
      $y++
    }until($y-gt$max)
    $x++
  }until($x-gt$max)