143704

Appears in sequences

• Number of ways to place two nonattacking queens on an n X n board.at n=23A036464
• Triangle read by rows: T(n,k) = 3*T(n-1,k-1) + 3*T(n-1,k) - 2*T(n-2,k-1) with T(n,0) = T(n,n) = 1.at n=48A152613
• Triangle read by rows: T(n,k) = 3*T(n-1,k-1) + 3*T(n-1,k) - 2*T(n-2,k-1) with T(n,0) = T(n,n) = 1.at n=51A152613
• G.f. satisfies A(x) = ( 1 + x*A(x)^2 / (1 - x*A(x))^3 )^2.at n=6A365151