90223

Appears in sequences

• Sum of the sizes of the seventh blocks in all set partitions of {1,2,...,n}.at n=4A270499
• a(0) = 0; a(n) = n - (1/n) * Sum_{k=1..n-1} binomial(n,k)^2 * (n-k) * k * a(k).at n=7A337590