# A144894 (b-file synthesized from sequence entry)
0 1
1 5
2 55
3 485
4 4380
5 39570
6 421800
7 4265100
8 49455000
9 594001800
10 7784683200
11 107814672000
12 1624964544000
13 25881953328000
14 443107288512000
15 8028628336512000
16 154539996629760000
17 3135393617489280000
18 67045955961922560000
19 1503619681171829760000
20 35321502985569884160000