# A006387 (b-file synthesized from sequence entry)
0 0
1 0
2 1
3 6
4 40
5 320
6 2946
7 29364
8 309558
9 3365108
10 37246245
11 416751008
12 4696232371
13 53186743416
14 604690121555
15 6896534910612
16 78867385697513
17 904046279771682
18 10384916465797240
19 119522063788612992
20 1378014272286250059