60397977600domain: NAppears in sequencesa(n) = n^2*4^n/4.at n=15A086952Number of directed Hamiltonian paths in the 2n-crossed prism graph.at n=22A137885Numerators of the terms of Lehmer's series S_2(2), where S_k(x) = Sum_{n>=1} n^k*x^n/binomial(2*n, n).at n=29A259852