I'm looking for a program that can:

* combine several PDFs so that the first page of each PDF has an odd page number in the combined document (e.g. by inserting a blank page if needed at the end of PDFs that have an odd number of pages)

If possible:

* easy to use (e.g. no need to write some scripts)
* work on Windows 7, but other Windows or Linux is OK too
* free

Surprisingly, [Adobe Acrobat Pro XI does not seem to allow such a PDF combination easily](https://superuser.com/q/723097/116475) (if you know how to do it with Adobe Acrobat Pro XI, please add an answer in the linked question, but ideally I'm looking for an easier/cheaper solution).