319769

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=21A048071
• Number of nonempty subsets of {1,2,...,n} in which exactly 1/2 of the elements are <= (n+3)/3.at n=21A048082
• a(n) = binomial(n+8,8) - 1.at n=14A165618
• Number of nX6 0..3 arrays with diagonals and antidiagonals unimodal and rows nondecreasing.at n=2A224389
• T(n,k)=Number of nXk 0..3 arrays with diagonals and antidiagonals unimodal and rows nondecreasing.at n=30A224391
• Number of 3 X n 0..3 arrays with diagonals and antidiagonals unimodal and rows nondecreasing.at n=5A224392
• a(n) = number of nonempty subsets S of {1,2,...,n} such that (number of nonprimes in S) = (number of primes in S).at n=22A369854