2238390domain: NAppears in sequencesTriangle of C(n+1,k)*C(2*n-3*k,n-3*k)/(n+1) by rows.at n=42A073187Number of ways of arranging n chords on a circle (handshakes between 2n people across a table) with exactly 2 simple intersections.at n=11A074922Numbers with prime factorization pqrstuv^2.at n=14A190381