122391522domain: NAppears in sequencesTriangle, read by rows, where T(n,k) = C(C(n+2,3) - C(k+2,3), n-k) for n >= k >= 0.at n=39A126445Number of 1-orbits of the cyclic group C_4 for a bi-colored square n X n grid with n squares of one color.at n=20A276449