1,3

By 'binary tree' we mean a rooted, ordered tree in which each vertex has either 0 or 2 children.

Eric S. Rowland, Pattern avoidance in binary trees.

Generating function f(x) satisfies x f(x)^3 + (-2 x^2 + 3 x - 1) f(x)^2 + x (x^2 - 3 x + 1) f(x) + x^3 = 0

Sequence in context: A108626 A159772 A161898 this_sequence A159773 A159769 A159771

Adjacent sequences: A159767 A159768 A159769 this_sequence A159771 A159772 A159773

nonn

Eric S Rowland (erowland(AT)math.rutgers.edu), Apr 23 2009