17999936497domain: NAppears in sequencesG.f.: 1/(1-x-16*x^2).at n=16A168579a(n) = (4*n + 1)^(1/2)/(4*n + 1)*((1 - p)*q^n - (1 - q)*p^n), where p = (1 - (4*n + 1)^(1/2))/2 and q = (1 + (4*n + 1)^(1/2))/2.at n=15A171180