480784678912domain: NAppears in sequencesa(n) = -2*a(n-1) + 4*a(n-2), a(0) = 1, a(1) = 0.at n=24A086344a(n) = 2*a(n-1) + 4*a(n-2) with n>1, a(0)=0, a(1)=4.at n=23A209084