A098543 Column 2 of triangle A098542, which shifts left and up under the matrix square.

1, 4, 12, 44, 236, 2028, 29164, 719340, 30943724, 2350770668, 318680099308, 77793540073964, 34472347123476972, 27928291976711924204, 41631598900551078537708, 114829789064202679162399212

Offset: 2

Author

Paul D. Hanna, Sep 16 2004

Keywords

• nonn

Comments

Related to A002449, the number of different types of binary trees of height n.

Crossrefs

Cf. A002449, A098542, A098544.

Formula

G.f.: A(x) = x*(1+x)/(1-x)*(G002449(x)-1), where G002449(x) is g.f. of A002449.