259152domain: NAppears in sequencesNumber of -n..n arrays x(0..3) of 4 elements with zero sum and no two consecutive zero elements.at n=35A199531a(n) = 5 + 4^n + 3*((-i*sqrt(7) - 3)^n + (i*sqrt(7) - 3)^n)/2^n.at n=8A370846