Abstract
We introduce a statistic
pmaj
(
P
)
for partitions of
[
n
]
, and show that it is equidistributed with
cr
2
, the number of 2-crossings, over all partitions of
[
n
]
with given sets of minimal block elements and maximal block elements. This generalizes the classical result of equidistribution for the permutation statistics inv and maj.