68327domain: NAppears in sequencesa(n) = 4*n^3 - 3*n^2 + 2*n - 1.at n=25A131464Triangle read by rows: T(n,k) is the number of free polyforms consisting of k unit square cells and n-k isosceles right triangular cells whose short sides have unit length. Cells are joined along sides of equal lengths.at n=39A391193