# A233438 (b-file synthesized from sequence entry)
0 0
1 2
2 6
3 30
4 210
5 2310
6 30030
7 510510
8 9699690
9 223092870
10 6469693230
11 200560490130
12 2153462358810
13 72490129383210
14 1958274892758030
15 58665460642891410
16 50035643372444730
17 19221664375883039070
18 1123712842678138983270
19 27456249893723439879090
20 350421246400567367415390