A figurate number stack is built using only the digits 0 through 9 exactly once.

Each tier is a figurate number of the order labelled; no number has a leading zero.


How many solutions can you offer?

(In reply to re: a solution by brianjn)

In puzzling over what "unit" meant in this context, another thought had entered my mind: a number that's not a figurate number, such as 2, 7 and 8.  Along with the possibility of 1, in the usual definition, or something else entirely (such as "can be arranged in a straight line"), I listed all the possibilities with a caveat that I didn't really know what was meant.

Edited on December 18, 2008, 11:24 am

Posted by Charlie on 2008-12-18 11:22:06