1150976domain: NAppears in sequencesNumber of labeled intersecting set-systems with no singletons covering some subset of {1,...,n}.at n=5A306000a(n) is the smallest k such that the sum of the first k primes is >= 10^n.at n=13A323362Number of (undirected) Hamiltonian paths in the 2 X n king graph.at n=10A339760