3814273domain: NAppears in sequencesa(0)=1, a(1)=1; thereafter a(n) = -a(n-1) - 2*a(n-2).at n=43A169998a(n) = 5*a(n-1) - 8*a(n-2), with a(0)=0, a(1)=1.at n=15A190969