54526

Appears in sequences

• Number of chiral pairs of polyominoes with n cells that have precisely the symmetry group of order 4 generated by 90-degree rotations.at n=44A144553
• Number of Dyck paths of semilength n such that the minimal number of peaks over all positive levels equals three.at n=12A288542
• G.f.: Sum_{n>=0} (n+1) * x^n * ((1+x)^n + 1)^n / (1 + x*(1+x)^n)^(n+2).at n=9A326006
• Free chiral polyominoes with n squares, having 90-degree rotational symmetry about the center of a square of the underlying square matrix.at n=44A351142