The uniform matroid
is the matroid on an
-element ground set whose independent
sets are exactly the subsets of
size at most
,
where
.
Its matroid rank is
, and its matroid bases are
all the
-element
subsets. In particular it has
matroid bases.
A parallel -thickening
replaces each ground set element by a parallel class
of
elements. Chen et al. (2026) proved that every such thickening of
with
and
satisfies the multiplicative Merino-Welsh
conjecture. For
,
they found that 62 is the smallest number of elements in a counterexample within
this family, attained by doubling each element of
. This minimum is not asserted over all matroids.