# A164741 (b-file synthesized from sequence entry)
0 1
1 6
2 30
3 150
4 750
5 3750
6 18750
7 93750
8 468735
9 2343600
10 11717640
11 58586400
12 292923000
13 1464570000
14 7322625000
15 36612000000
16 183054375210
17 915243753000
18 4576078154040
19 22879687737000
20 114394923627000
21 571957043385000