49958

Appears in sequences

• Free polyominoes with 2n squares, having 180-degree rotational symmetry about a square mid-side.at n=9A234010
• a(n) is the least positive integer b such that b^(2^n) + (b-1)^(2^n) is prime.at n=15A253633
• a(n) is the number of polyedges with n edges in the {4,5} tessellation of the hyperbolic plane.at n=7A390201