50067108
domain: N
Appears in sequences
- a(n) = binomial(3*n,n)/(2*n+1) (enumerates ternary trees and also noncrossing trees).at n=12A001764
- Number of necklaces with 12 black beads and n-12 white beads.at n=25A032197
- If n = 2*m then a(n) = binomial(3*m, m)/(2*m+1), if n=2*m+1 then a(n) = binomial(3*m+1, m+1)/(2*m+1).at n=24A047749
- Number of dissectable polyhedra with n tetrahedral cells and symmetry of type F.at n=46A047760
- a(n) = A047760(2n+1).at n=23A047761
- Number of dissectable polyhedra with n tetrahedral cells and symmetry of type P.at n=47A047765
- a(n) = A047765(2n).at n=23A047767
- a(n) = binomial(prime(n),n)/prime(n) where prime(n) = n-th prime.at n=11A075872
- Interpolation of A001764(n+1) and A006629(n).at n=22A124817
- Triangle read by rows: T(n,k) = number of connected matchings with n crossings and k chords, in a disk, k=2..n+1.at n=77A232223
- a(n) = binomial(6*n, 2*n) / (4*n + 1).at n=6A235534
- a(n) = binomial(9*n, 3*n) / (6*n + 1).at n=4A235535
- Number of order ideals of type e^(1)_n.at n=21A299295
- a(n) = binomial(A007310(n+1),n)/A007310(n+1).at n=12A367520