# A199937 (b-file synthesized from sequence entry) 1 4 2 12 3 36 4 104 5 302 6 868 7 2490 8 7132 9 20424 10 58418 11 167036 12 477412 13 1364340 14 3898236 15 11138194 16 31824012 17 90926724 18 259790792 19 742259560 20 2120727868 21 6059178186 22 17311798890 23 49461883130 24 141318491362 25 403763748824