3108104

Appears in sequences

• Number of nonempty subsets of {1,2,...,n} in which exactly 1/2 of the elements are <= (n-2)/3.at n=27A048016
• Number of nonempty subsets of {1,2,...,n} in which exactly 1/2 of the elements are <= (n-3)/3.at n=27A048027
• a(n) = binomial(n+8,8) - 1.at n=20A165618