151920domain: NAppears in sequencesNumber of rooted trees with n nodes and 2-colored non-leaf nodes.at n=10A004113Numbers k such that k and 6*k are anagrams.at n=30A023090If the decimal expansion of n is d_1 ... d_k, a(n) = Sum d_i!*binomial(10,d_i).at n=36A306958