213000

Appears in sequences

• Łukasiewicz words (without the last zero) for rooted plane trees where non-leaf branching can occur only at the leftmost branch of any level, but nowhere else.at n=45A209644
• Triangle read by rows: rook numbers of certain "probleme des rencontres" boards of the second kind of size n X k (0 <= k <= n).at n=25A220905
• Number of nX2 0..3 arrays with no element equal to one plus the sum of elements to its left or three plus the sum of elements above it or one plus the sum of the elements diagonally to its northwest, modulo 4.at n=7A240456