50348

Appears in sequences

• Number of polyominoes with n cells, symmetric about two orthogonal axes.at n=36A056877
• Eigenvector of triangle A055151 of Motzkin polynomial coefficients, where A055151(n,k) = n!/((n-2k)!*k!*(k+1)!) for 0<=k<=[n/2], n>=0.at n=11A119020
• 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=36A351190
• a(n) = n^5/5 + n^3/3 + 7*n/15.at n=12A385894