# A147729 (b-file synthesized from sequence entry) 1 1 2 2 3 6 4 16 5 54 6 232 7 936 8 3880 9 17302 10 81584 11 409012 12 2138674 13 11754832 14 66857094 15 395646912 16 2421309886 17 15276353934