380522

Appears in sequences

• Number of polyominoes with n cells, symmetric about two orthogonal axes.at n=42A056877
• a(n) = 3^n + 7^n + 8^n.at n=6A074558
• Number of polyominoes of n cells with both horizontal and vertical symmetries, for which the 180-degree rotational symmetry has an axis that coincides with the center of a square, but without 90-degree rotational symmetry.at n=42A351190