311088

Appears in sequences

• Triangle of numbers {a(n,k), n >= 0, 0<=k<=n} defined by a(0,0)=1, a(n,0)=a(n-1,n-1), a(n,k)=a(n,k-1) + Sum_{i=0..k-1} a(n-1,i).at n=29A108041
• Number of (w,x,y,z) with all terms in {1,...,n} and w*x<=y*z+2.at n=28A212055
• Number of set partitions of {1,...,n} where each block's elements are pairwise coprime.at n=17A320423