2390004

Appears in sequences

• a(n) = Sum_{k=0..n-1} binomial(n-1,k)*binomial(n+k,k). Also a(n) = T(n,n), array T as in A049600.at n=10A047781
• a(n) = n^2*(2*n^8 + 120*n^6 + 1806*n^4 + 7180*n^2 + 5067)/14175.at n=10A099197
• Number of paths from (0,0) to the line x = n, each segment given by a vector (1,1), (1,-1), or (2,0), not crossing the x-axis, and including no horizontal segment on the x-axis.at n=19A247623
• Array read by antidiagonals: the number of directed elements with area n on the lattice T_{2k+1}.at n=67A296129