# A138550 (b-file synthesized from sequence entry)
0 1
1 0
2 1
3 1
4 5
5 16
6 75
7 366
8 2016
9 11936
10 75678
11 507575
12 3575693
13 26289408
14 200709665
15 1584482382
16 12888498820
17 107698656192
18 922140333952
19 8072379904752
20 72108967554160
21 656190909218560
22 6074106708205200
23 57118680813847840