Data update

Task/Abundant-odd-numbers/PowerShell/abundant-odd-numbers.ps1

@@ -0,0 +1,57 @@
+# Abundant odd numbers
+
+# Returns the sum of the proper divisors of $N
+function Divisor-Sum([uint32]$N) {
+  [uint32]$sum = 1
+  [uint32]$intSqrtN = [uint32]([Math]::Sqrt($N))
+  for ($d = 2; $d -le $intSqrtN; $d++) {
+    # The for loop is used because foreach goes downwards if $intSqrtN < 2
+    if ($N % $d -eq 0) {
+      $sum += $d
+      [uint32]$otherD = $N / $d
+      if ($otherD -ne $d) {
+        $sum += $otherD
+      }
+    }
+  }
+  return $sum
+}
+
+# first 25 odd abundant numbers
+[uint32]$oddNumber = 1
+[uint32]$aCount = 0
+[uint32]$dSum = 0
+Write-Output "The first 25 abundant odd numbers:"
+while ($aCount -lt 25) {
+  $dSum = Divisor-Sum $oddNumber
+  if ($dSum -gt $oddNumber) {
+    $aCount++
+    [string]$out = "{0, 6} proper divisor sum: {1, 6}" -f $oddNumber, $dSum
+    Write-Output $out
+  }
+  $oddNumber += 2
+}
+
+# 1000th odd abundant number
+while ($aCount -lt 1000) {
+  $dSum = Divisor-Sum $oddNumber
+  if ($dSum -gt $oddNumber) {
+    $aCount++
+  }
+  $oddNumber += 2
+}
+Write-Output "1000th abundant odd number:"
+Write-Output "    $($oddNumber - 2) proper divisor sum: $dSum"
+
+# first odd abundant number > 1000000000
+$oddNumber = 1000000001
+[bool]$found = $false
+while (-not $found) {
+  $dSum = Divisor-Sum $oddNumber
+  if ($dSum -gt $oddNumber) {
+      $found = $true
+      Write-Output "First abundant odd number > 1 000 000 000:"
+      Write-Output "    $oddNumber proper divisor sum: $dSum"
+  }
+  $oddNumber += 2
+}