Number of binary trees of height n; or products (ways to insert parentheses) of height n when multiplication is non-commutative and non-associative.
A001699
Number of binary trees of height n; or products (ways to insert parentheses) of height n when multiplication is non-commutative and non-associative.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =21a(4) =651a(5) =457653a(6) =210065930571
External references
- oeis: A001699