On 18 February 2018 at 10:58, Mark Rogers mark@more-solutions.co.uk wrote:
If the pages were A4 I could use pdftk: pdftk in.pdf cat 2-4 1 output out.pdf .. but pdftk can currently only "see" two A3 pages so that won't work.
As is so often the way, formulating the question in a way suitable to post to a mailing list also prompts new phrases to Google for so I solved this myself:
sudo apt install pdfposter pdftk pdfposter in.pdf -s1 tmp.pdf pdftk tmp.pdf cat 2 4 5 1 output a4.pdf
(For some reason, pdfposter gives me a 6 page result, where 1,2,4,5 have my document on them and 3&6 are blank. I could probably solve that if it mattered but as it's just an interim step easily fixed by pdftk I didn't bother.)
The OCR layer appears to have been retained correctly by this process.