# A212531 (b-file synthesized from sequence entry) 1 1 2 2 3 5 4 10 5 21 6 40 7 83 8 161 9 331 10 644 11 1102 12 3627 13 5646 14 10083 15 29188 16 53681 17 84121 18 237453 19 373114 20 1400757 21 2443494