# A331618 (b-file synthesized from sequence entry) 0 1 1 1 2 3 3 15 4 97 5 785 6 7523 7 83615 8 1053281 9 14838177 10 230832867 11 3929944623 12 72633052545 13 1447981700529 14 30960823851267 15 706676217730239 16 17145815895371073 17 440594781536265537 18 11952178787661839427 19 341291300477569866831 20 10231558345117929439521