255919domain: NPropertiesPrimalityPrimeyesAppears in sequencesNumber of vertically indecomposable distributive lattices on n nodes.at n=30A072361The n-th Chebyshev primes that are equal to the 2n-th primes.at n=2A196675G.f. satisfies A(x) = 1 + x*A(x) + x^5*A(x)^5.at n=18A364522Prime numbersat n=22518