2684928

Appears in sequences

• a(n) = Sum_{k=1..n} binomial(n,k) * tau(k) * tau(n - k + 1), where tau = A000005.at n=17A328681
• a(n) is the denominator of Product_{i=0..n-1} (n-i)^((-1)^ceiling(i/2)).at n=28A337355