Number T(n,k) of colored set partitions of [n] where colors of the elements of subsets are distinct and in increasing order and exactly k colors are used; triangle T(n,k), n>=0, 0<=k<=n, read by rows.
Peter Kagey
OEIS sequence A322670 by Alois P. Heinz (August 2019).
(Even terms are drawn as dark hexagons and odd terms are drawn as light hexagons.)
