# A005618 (b-file synthesized from sequence entry) 0 4 1 16 2 88 3 520 4 3112 5 18664 6 111976 7 671848 8 4031080 9 24186472 10 145118824 11 870712936 12 5224277608 13 31345665640 14 188073993832 15 1128443962984 16 6770663777896 17 40623982667368 18 243743896004200 19 1462463376025192