hp 28s - creating nested lists

[Werner]

? It works for me.
When you say the code has errors, does it not compile or does it not run?
Does the 28 have a FOR .. STEP statement? If not, then you can't use this version and will have to stick to one of the two others.
(I don't have a 28)
If it compiles, then you must've entered a typo..

NDUPN is a useful little subprogram.. I always try to make 'beautiful' code, ie. short yet clear, and this way it's both ;-) And perhaps NDUPN can be used elsewhere?

Cheers, Werner