2646723
domain: N
Appears in sequences
- Schroeder's second problem (generalized parentheses); also called super-Catalan numbers or little Schroeder numbers.at n=11A001003
- Semiprimes in A001003.at n=1A101619
- Triangle read by rows: T(n,k) is the number of Delannoy paths of length n, having k EE's and NN's crossing the line y = x (i.e., two consecutive E steps from the line y = x+1 to the line y = x-1 or two consecutive N steps from the line y = x-1 to the line y = x+1).at n=46A110123