519711666

Appears in sequences

• Number of general plane trees whose n-th subtree from the left is equal to the n-th subtree from the right, for all its subtrees (i.e., are palindromic in the shallow sense).at n=19A073192
• Convolution of A000108 (Catalan numbers) with A126120 (Catalan numbers interpolated with 0's).at n=18A161006