20793

Appears in sequences

• Schroeder's second problem (generalized parentheses); also called super-Catalan numbers or little Schroeder numbers.at n=8A001003
• Table T(n,k), n>=0 and k>=0, read by antidiagonals: the k-th column given by the k-th Narayana polynomial.at n=57A008550
• Erroneous version of A001003.at n=8A010682
• Triangle of numbers S(x,y) = number of lattice paths from (0,0) to (x,y) that use step set { (0,1), (1,0), (2,0), (3,0), ....} and never pass below y = x.at n=44A011117
• Expansion of (3+2*x^2)/(1-x)^4.at n=28A037236
• Signed super-Catalan or little Schroeder numbers.at n=8A080243
• a(n) = 1 + Sum(prime(i)*(2*i-1): 1<=i<=n).at n=20A083215
• Triangle read by rows: T(n,k) is number of Schroeder paths of length 2n and having k peaks at height 1, for 0 <= k <= n.at n=36A104219
• 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=22A110123
• Triangular array formed by the little Schröder numbers s(n,k).at n=28A110440
• Triangle read by rows: T(n,k) is the number of bicolored Dyck paths of semilength n and having k peaks of the form ud (0 <= k <= n). A bicolored Dyck path is a Dyck path in which each up-step is of two kinds: u and U.at n=36A114608
• Numbers k such that k and 2*k, taken together are pandigital.at n=14A115922
• Triangle related to super-Catalan numbers (or little Schroeder numbers).at n=43A130743
• Triangle related to super-Catalan numbers (or little Schroeder numbers).at n=44A130743
• Triangle read by rows: T(n,k) is the number of paths of length n in the first quadrant, starting at the origin, ending at height k and consisting of 2 kind of upsteps U=(1,1) (U1 and U2), 3 kind of flatsteps F=(1,0) (F1, F2 and F3) and 1 kind of downsteps D=(1,-1).at n=28A134426
• Number of permutation symbols of type *a(n) for hyperbolic archimedean tessellations of rank n.at n=15A142870
• A bisection of A142870.at n=7A142876
• Eigentriangle, row sums = A006318.at n=36A144156
• Eigentriangle, row sums = A006318.at n=46A144156
• Super-Catalan triangle (read by rows) = triangular array associated with little Schroeder numbers (read by rows): T(0,0)=1, T(p,q) = T(p,q-1) if 0 < p = q, T(p,q) = T(p,q-1) + T(p-1,q) + T(p-1,q-1) if -1 < p < q and T(p,q) = 0 otherwise.at n=43A144944