# A005978 (b-file synthesized from sequence entry) 1 0 2 0 3 0 4 0 5 1 6 4 7 19 8 93 9 539 10 3474 11 24856 12 192972 13 1613219 14 14410374 15 136920388 16 1378542639 17 14663082556 18 164340455701 19 1936286904952 20 23932267735948 21 309701296575063