270300domain: NAppears in sequencesAntidiagonal sums of the convolution array A213822.at n=23A213824Expansion of (1/(1 - x)) * Sum_{k>=0} x^(2*k) / Product_{j=1..2*k} (1 - x^j).at n=45A304620Number of (undirected) Hamiltonian paths in the n-dipyramidal graph.at n=31A307939