# A148680 (b-file synthesized from sequence entry) 0 1 1 1 2 3 3 7 4 21 5 73 6 245 7 793 8 2815 9 10075 10 36727 11 137411 12 511099 13 1902023 14 7265539 15 27944559 16 107626613 17 418427913 18 1633245101 19 6388652625 20 25192946761 21 99781420877 22 395823365473 23 1577503839685 24 6310009049517 25 25281085381601 26 101614792870501 27 409704814929945 28 1654942675306197