325909584

Appears in sequences

• Number of permutations of 0..floor((n*4-1)/2) on even squares of an n X 4 array such that each row and column of even squares is increasing.at n=9A215288
• Triangle read by rows: T(n,k) = (3*n - 2*k)!/((n-k)!^3*k!).at n=29A318107
• a(n) = (3*n + 1)!/(n!)^3.at n=6A331322
• Number of tree-rooted planar maps with n+1 vertices and n+1 faces.at n=5A342983
• a(n) = denominator( (-1)^(n-1)*H(2*n)/(2*n + 1) ), where H(n) is the n-th harmonic number.at n=10A392690