23284800

Appears in sequences

• Triangular array read by rows. T(n,k) is the number of chain topologies on an n-set with exactly k open sets where one of the open sets is a single point set, n >= 2, 3 <= k <= n+1.at n=42A282507
• Integers k such that A000010(k) <= A008480(k).at n=10A364750
• Positive integers k such that the set {d+k/d : d|k} contains four consecutive integers.at n=4A386303
• E.g.f. A(x) satisfies A(x) = 1 - x*A(x)^3 * log(1 - x^2*A(x)^2).at n=10A392934