222000

Appears in sequences

• Łukasiewicz words for the rooted plane binary trees (interpretation d in Stanley's exercise 19) with the last leaf implicit, i.e., these words are given without the last trailing zero, except for the null tree which is encoded as 0.at n=8A071152
• a(n) = (1/2)*(n^4 + 11*n^3 + 53*n^2 + 97*n + 54).at n=24A129026
• Odd-indexed terms of A129026.at n=12A129027
• 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=43A209644