# A308338 (b-file synthesized from sequence entry) 0 1 1 1 2 2 3 9 4 44 5 270 6 2064 7 17682 8 171296 9 1867968 10 22470840 11 294493320 12 4195969392 13 64416698112 14 1059685905264 15 18609306423120 16 347179119075840 17 6855335163907200 18 142889687354283264 19 3133647091691585280 20 72124075333003155840 21 1738384773846440146560