39028domain: NAppears in sequencesa(n) = 2*a(n-1) - a(n-4) for n >= 4, where a(0) = 2, a(1) = 4, a(2) = 6, a(3) = 10, a(4) = 16.at n=17A288599The fixed points of A355636.at n=19A355637