Right, so after an entire day of trying everything we can think of, it would appear n8n is possibly not capable of doing this seemingly simple thing, as per Jan’s comment
In light of that, is anyone feeling kind enough to possibly think of any workarounds?
Effectively, within a loop, we need to do maths on a variable which starts at a set value (and therefore we suspect has to be set outside of the loop as per the initial workflow we posted.)
It might help to think of it as running a counter in a loop but starting at a set number instead of zero. A global variable could work as well I guess but with n8n being so comprehensive, we figured there surely must be an easy method to achieve this and surely can’t be the first people for such a frequent requirement.
(Please let us know if this is best posted in a new thread for the rules but also to get more exposure.)