# A030910 (b-file synthesized from sequence entry)
1 2
2 4
3 12
4 49
5 249
6 1499
7 10493
8 83946
9 755519
10 7555194
11 83107140
12 997285682
13 12964713872
14 181505994212
15 2722589913192
16 43561438611080
17 740544456388374
18 13329800214990740
19 253266204084824069
20 5065324081696481381