# A143388 (b-file synthesized from sequence entry)
0 1
1 2
2 8
3 40
4 221
5 1288
6 7752
7 47652
8 297275
9 1874730
10 11920740
11 76292736
12 490828828
13 3171317360
14 20563942288
15 133749903324
16 872196460359
17 5700580759510
18 37332393806400
19 244914161562840
20 1609234420792845