281248448936
domain: N
Appears in sequences
- a(n) is the number of n-step walks on square lattice such that 0 <= y <= x at each step.at n=23A005558
- Central column of triangle A090181.at n=12A125558
- Number of 2 X 11 matrices with elements in 0..n with each row and each column in nondecreasing order. 2,11,n can be permuted, see formula.at n=12A140934
- a(n) = binomial(m+n-1,n)^2 - binomial(m+n,n+1)*binomial(m+n-2,n-1) with m = 14.at n=11A169937