1551580888

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=19A005558
• Central column of triangle A090181.at n=10A125558
• Tenth column (and diagonal) of Narayana triangle A001263.at n=10A134291
• a(n) = binomial(m+n-1,n)^2 - binomial(m+n,n+1)*binomial(m+n-2,n-1) with m=12.at n=9A140925
• Number of 9 X 10 matrices with elements in 0..n with each row and each column in nondecreasing order. 9,10,n can be permuted, see formula.at n=2A140932