OFFSET
1,2
COMMENTS
a(n) is also the number of tie-permitting labeled histories for a fully symmetric labeled topology with 2^n leaves.
LINKS
M. C. King and N. A. Rosenberg, A mathematical connection between single-elimination sports tournaments and evolutionary trees, Math. Mag. 96 (2023), 484-497.
FORMULA
a(n) = Sum_{k=n..2^n-1} A380166(n,k).
EXAMPLE
For n=2 and a tournament with structure ((A,B),(C,D)), game (A,B) can be played before, after, or simultaneously with game (C,D), producing a(2)=3.
CROSSREFS
KEYWORD
nonn,new
AUTHOR
Noah A Rosenberg, Jan 01 2025
STATUS
approved