# A131014 (b-file synthesized from sequence entry)
1 4
2 61
3 274
4 1764
5 13068
6 109584
7 1026576
8 10628640
9 120543840
10 1486442880
11 19802759040
12 283465647360
13 4339163001600
14 70734282393600
15 1223405590579200
16 22376988058521600
17 431565146817638400
18 8752948036761600000
19 186244810780170240000
20 4148476779335454720000