170543
domain: N
Appears in sequences
- Number of nonempty subsets of {1,2,...,n} in which exactly 1/2 of the elements are <= n/3.at n=21A047193
- Number of nonempty subsets of {1,2,...,n} in which exactly 1/2 of the elements are <= (n-1)/3.at n=21A048005
- Number of nonempty subsets of {1,2,...,n} in which exactly 1/2 of the elements are <= (n+1)/3.at n=21A048038
- a(n) = C(n,7)-1.at n=15A124090