# A012321 (b-file synthesized from sequence entry)
0 0
1 1
2 2
3 5
4 20
5 125
6 830
7 6001
8 45768
9 394553
10 3699418
11 38758909
12 433324828
13 5299232757
14 68428221654
15 958395448297
16 14101599762448
17 223667919165041
18 3706771205012274
19 65843651814440309
20 1215858569345385636