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 20081218 11:22:06 