`pdfpages` `\includepdf`'s page list input options

Question

I'd like to use pdfpages to make a print layout of my documents, in order to print them in A4 paper, but with 2 pages per page. The problem is setting the page order in a way I can cut the printed A4 sheets down to A5 size and have page 2 of the original document in the opposite side of page 1, in the same A5 sheet.

For this I would need something like:

\includepdf[pages={1,3,2,4,5,7,6,8},% ASSUMING A 8 PAGES FILE.
nup=1x2,landscape=true]{OriginalDoc.pdf}

And rotate also 180º pages 2,4,6,8, ... if the printer dialogue doesn't allow for that.

The first problem is building this ordered list for a n pages file working only inside \includepdf options. The second one, the rotation. After reading pdfpages' manual, I see there are no many options for building the pages list.

If this approach is not possible, how would I build a loop like:

FOR i FROM 1 TO n-3 WITH INCREMENT(i)=4 DO
  \includepdf[pages={i,i+2},nup=1x2,landscape=true]{OriginalDoc.pdf}
  \includepdf[pages={i+1,i+3},angle=180,nup=1x2,landscape=true]{OriginalDoc.pdf}
END DO

? Or what other ideas may help me?

Answer 1

Using the signature option of the pdfpages package should do the trick:

\includepdf[signature=4]{OriginalDoc.pdf}