Hi, Thanks for contacting us.
Could you let me know a little more information about what you are trying to achieve? You can't export the Y sequence count from the sequence node, but there is a segment counter accessible in the Arithmetic node. Just change the mode to expression and use
return SegmentYCounter;
There are two separate counters: one for default segments, and another for the Start, End, Corner, and Evenly.
I hope that helps, please let me know if there's anything else I can help with.
All the best,
Paul