117756domain: NAppears in sequencesEight bishops and one elephant on a 3 X 3 chessboard: a(n)= (3^(n+1)-Jacobsthal(n+1))-(3^n-Jacobsthal(n)), with Jacobsthal=A001045.at n=10A175659Number of fixed polyominoids with n cells, allowing right-angled corner-connections.at n=4A366000