# A124532 (b-file synthesized from sequence entry) 0 1 1 1 2 3 3 10 4 39 5 174 6 858 7 4564 8 25793 9 153301 10 951325 11 6130757 12 40861658 13 280767621 14 1983859580 15 14385651988 16 106878699675 17 812480791324 18 6312686006725 19 50083418434737 20 405430892640225 21 3346568909331984