A156129 Q_n(2) (see A104035).

1, 2, 9, 58, 501, 5402, 69909, 1055458, 18211401, 353506802, 7624471809, 180889942858, 4681743794301, 131269240120202, 3963720131525709, 128234893954822258, 4425253713052509201, 162255367355408805602, 6299173242134303391609, 258136328705500135053658

Offset: 0

Author

N. J. A. Sloane, Nov 06 2009

Keywords

• nonn

Formula

G.f.: 1/Q(0), where Q(k) = 1 - 2*x*(2*k+1) - 5*x^2*(k+1)^2/Q(k+1); (continued fraction). - Sergei N. Gladkovskii, Sep 28 2013