67030785

Appears in sequences

• Number of restricted hexagonal polyominoes with n cells.at n=14A002212
• Number of polyhexes with n hexagons, having reflectional symmetry (see Harary and Read for precise definition).at n=27A002215
• a(n) = a(1)*a(n-1) + a(2)*a(n-2) + ...+ a(n-2)*a(2) for n >= 3.at n=14A025238
• G.f. satisfies A(x) = (1 + x) * (1 + x/A(x)).at n=15A366325