16692480

Appears in sequences

• Number of deco polyominoes of height n, having no 2-cell columns starting at level 0. A deco polyomino is a directed column-convex polyomino in which the height, measured along the diagonal, is attained only in the last column.at n=10A121635
• E.g.f.: A(x) = x + tanh(A(x)^2).at n=7A226760
• Number of ordered pairs of permutation functions on n elements satisfying f(f(x)) = g(f(g(x))).at n=9A239837