11453246121domain: NAppears in sequencesa(n) = (8*4^n - 5)/3.at n=16A083584Expansion of x*(1+2*x)/((1+x)*(1-x)*(1-2*x)).at n=33A084639a(n) = 3*a(n-1) -2*a(n-2) -a(n-3) +3*a(n-4) -2*a(n-5) for n > 4, with initial values as shown.at n=35A166022