Colombo's determinant problem asks when the matrix 
with entries 
has nonzero determinant
for distinct real numbers 
, 
,
..., 
and a positive integer 
. The proposed characterization, attributed to Colombo's
work by Ma (2026), is the following for 
.
The determinant is nonzero iff 
and either 
or 
is even.
Two obstructions explain the necessary conditions. Expanding the powers gives matrix rank at most 
, so 
forces singularity. If 
is odd, the matrix is skew symmetric and therefore has zero
determinant when 
is odd. For 
,
its determinant is 
and never vanishes.
Ma (2026) reported a proof of the remaining case, even 
and odd 
, together with a Lean formalization. The even-exponent
case follows from earlier results discussed in that paper. The proof
was developed with AI assistance, and Li et al. (2026) supplied an independent
proof. Journal publication of these reports had not been
confirmed as of Sep. 7, 2026.
