7745024domain: NAppears in sequencesa(n)*a(n+3) - a(n+1)*a(n+2) = 2^n, given a(0)=1, a(1)=1, a(2)=2.at n=21A080877a(n)*a(n+3) - a(n+1)*a(n+2) = 2^n, given a(0)=1, a(1)=1, a(2)=3.at n=20A080878Expansion of (1-3*x)/(1 - 6*x + 4*x^2).at n=10A098648