A331114 Number of rooted trees with 2-colored non-root nodes with an n nodes of each color.

1, 3, 37, 596, 11513, 245356, 5597060, 133950215, 3323281496, 84787933926, 2212123329500, 58779046239904, 1585796125188065, 43337540217740908, 1197492197496481744, 33406620056723507124, 939775084670916268134, 26632926871927867655261, 759732892913483065912296

Offset: 0

Author

Andrew Howroyd, Jan 09 2020

Keywords

• nonn

Comments

The total number of nodes including the root is 2n + 1.

Examples

			a(1) = 3 because there are three trees with one root node and one additional node of each color:
   1 -- o -- 2,
   o -- 1 -- 2,
   o -- 2 -- 1.
		

Links

• Andrew Howroyd, Table of n, a(n) for n = 0..100

Crossrefs

Cf. A304489, A329055, A331113.

Formula

a(n) = A304489(2*n+1, n).