-87380domain: ZAppears in sequencesa(n) = -a(n-1) + 2*a(n-2), a(0)=1, a(1)=2.at n=18A084247Expansion of (1+x-4*x^2) / ((1+x)*(1-4*x^2)).at n=18A087213a(n) = (1/3)*(1 - (-2)^n + 3*(-1)^n ) = (-1)^(n+1)*A167030(n).at n=18A167193First term of n-th difference sequence of (floor(k*r)), r = sqrt(8), k >= 0.at n=19A325674