63465

Appears in sequences

• Triangular array read by rows: T(n,k) is the number of ways to partition an n-set into exactly k blocks and then partially order the blocks, n>=1, 1<=k<=n.at n=19A247231
• Triangle read by rows: T(n,k) = number of topologies on an n-set X such that there are exactly k elements in X that are topologically distinguishable, n >= 0, 0 <= k <= n.at n=25A280192
• Expansion of Product_{k>=1} (1 + x^k)^A002131(k).at n=21A301798