172246

Appears in sequences

• Number of 2 X 2 matrices with all elements in {0,1,...,n} and determinant >= 2n.at n=25A210367
• Number of polyominoes of 2n cells with both diagonal symmetries, for which the 180-degree rotational symmetry has an axis that coincides with a vertex of a square, but without 90-degree rotational symmetry.at n=22A351160