# A107840 (b-file synthesized from sequence entry) 1 1 2 1 3 1 4 0 5 4 6 8 7 25 8 63 9 169 10 440 11 1156 12 3024 13 7921 14 20735 15 54289 16 142128 17 372100 18 974168 19 2550409 20 6677055 21 17480761 22 45765224 23 119814916 24 313679520 25 821223649 26 2149991423 27 5628750625 28 14736260448 29 38580030724 30 101003831720