156864domain: NAppears in sequencesNumber of ways to place a non-attacking white and black knight on n X n chessboard.at n=19A035289Table with g.f. [1-x*n-sqrt(x^2*n^2-2*n*x+1+4*x^2-4*x)]/(2*x).at n=63A128888a(n) = 8*Sum_{k=0..n} 7^k.at n=5A146885Expansion of (1-2x-sqrt(1-8x+8x^2))/(2x).at n=8A166229