# A083691 (b-file synthesized from sequence entry)
0 1
1 2
2 6
3 20
4 76
5 296
6 1240
7 5200
8 22960
9 100512
10 458592
11 2064704
12 9633472
13 44237440
14 209780096
15 977536256
16 4693031680
17 22117091840
18 107211650560
19 509817656320
20 2490609167360
21 11930278307840
22 58656838113280
23 282679983493120