175976

Appears in sequences

• Number of (n+1) X 5 0..1 matrices with each 2 X 2 subblock idempotent.at n=18A224546
• Triangle read by rows: T(n,k) is the number of planar tanglegrams of size n with 0 <= k < n leaf-matched pairs. A leaf matched pair is a pair of non-leaf vertices (u,v) in the tanglegram such that the induced subtrees rooted and u and v also form a tanglegram (equivalently, the leaves in these two subtrees are matched by the matching that forms the original tanglegram).at n=50A349409