994309609247domain: NAppears in sequencesSum of all n-digit Pell numbers.at n=11A131621a(n) = Pell(n) * Sum_{d|n} 1/Pell(d), where Pell(n) = A000129(n).at n=31A203797Part of the y solutions of the Pell equation x^2 - 2*y^2 = +7.at n=15A253811