A067325 Fourth column of triangle A067323.

5, 19, 66, 227, 785, 2739, 9646, 34268, 122706, 442510, 1605956, 5861481, 21502585, 79243395, 293246550, 1089264360, 4059928950, 15179606010, 56917649820, 213982542150, 806429435994, 3046017513198

Offset: 0

Author

Wolfdieter Lang, Feb 05 2002

Keywords

• nonn
• easy

Comments

Also fourth diagonal of triangle A028364.

Crossrefs

Cf. A067324 (third column).

Formula

a(n)= A067323(n+3, 3)= C(n+4)-(C(n+3)+C(n+2)+2*C(n+1)), C(n) := A000108(n) (Catalan).

G.f.: (c(x)^3)*(2+2*c(x)+c(x)^2), with c(x) g.f. of A000108 (Catalan).