C_{0} = 1\\C_{1} = 1\\C_{2} = 2\\C_{3} = 5\\C_{4} = 14\\C_{5} = 42\\C_{6} = 132\\C_{7} = 429\\C_{8} = 1430\\C_{9} = 4862\\C_{10} = 16796\\C_{11} = 58786\\C_{12} = 208012\\C_{13} = 742900\\C_{14} = 2674440\\C_{15} = 9694845\\C_{16} = 35357670\\C_{17} = 129644790\\C_{18} = 477638700\\C_{19} = 1767263190\\C_{20} = 6564120420\\