5093330domain: NAppears in sequencesNumber of length n+3 0..2 arrays with no four consecutive terms having the sum of any three elements equal to three times the fourth.at n=12A249284G.f. = b(2)*b(4)*b(6)/(x^8+x^6-x^5+x^4-2*x^3-x+1), where b(k) = (1-x^k)/(1-x).at n=30A266340