Exporting only odd page number from Indesign

> You can use formula in Excel to convert numbers to letters, etc. 

But page 'numbers' can include section prefixes, so you can have page numbers/folios such as 'A12' or '27-C'.

James's idea to print to the PDF driver is interesting, but it won't let you select a preset or make any other adjustments. Uwe's idea of using a spreadsheet or some way to generate a list of odd or even numbers works only if the pages are numbered with plain Arabic numbers (and you need to know the document's extent). That leaves Barb's idea of a script, see below.

To use it, open the document you want to export and run the script. At the prompt, type odd or even and click OK. The script copies a string with page numbers (rectos or versos) to the clipboard.

Then export the document, and copy the page string into the 'Range:' field.

(Unfortunately it's not possible to pre-set or pre-fill the PDF export dialog, so the script plugs the string in a temporary text frame, copies its content, and removes it. Rather than removing the frame the script undoes its addition so that it leaves no footprint in the document.)

(function () {
  
  var reply = prompt ('Enter odd or even', 
    'odd', 'Print odd or even pages');
  if (!reply) {
    exit();
  }
  if (reply.toLowerCase() === 'odd') {
    start = 0;
  } else if (reply === 'even') {
    start = 1;
  } else {
    exit();
  }
      
  var s = '';
  var pp = app.activeDocument.pages.
    everyItem().getElements();
  for (var i = start; i < pp.length; i=i+2) {
    s += pp[i].name + ',';
  }
  var frame = app.activeDocument.textFrames.add ({
    contents: s.replace(/,$/,''),
  });
  frame.parentStory.paragraphs[0].select();
  app.copy();
  app.activeDocument.undo();
}());

Hi @Matthias N.:

Scripting extends InDesign's default functionality, but within the InDesign feature set, the only option to use Export to PDF is to type in the pages you want and separate them with a comma.

Range: 1,3,5,7,9,11 etc

Not very helpful for a long document unless you do it all the time, in which case you could type in once and  copy/paste that string from another file when you need it. 

~Barb

Export (to PDF, at least) doesn't have an even-odd option. However, you can Print to the PDF driver and have the even or odd page output choices.