# A012712 (b-file synthesized from sequence entry) 0 0 1 1 2 2 3 7 4 36 5 285 6 2470 7 25891 8 304584 9 4116473 10 61307338 11 1011045759 12 18130445036 13 353222430613 14 7401849057902 15 166375042595867 16 3987022624401808 17 101564702642995953 18 2738893925584229778 19 77978462505905882103 20 2336771614133464558516 21 73533230212519134743821