# A099748 (b-file synthesized from sequence entry) 0 1 1 2 2 21 3 225 4 3328 5 33518 6 257909 7 1544907 8 7657779 9 32454761 10 121100938 11 405911691 12 1242567609 13 3517715389 14 9305703095 15 23194232130 16 54848107788 17 123760738779 18 267768667311 19 557808040826 20 1122804257019 21 2190539008704 22 4153269969884 23 7670791137960