# A052631 (b-file synthesized from sequence entry)
0 0
1 1
2 4
3 30
4 288
5 3480
6 50400
7 851760
8 16450560
9 357436800
10 8629286400
11 229162348800
12 6638962176000
13 208362342988800
14 7042436719718400
15 255029193619200000
16 9851119008546816000
17 404305986955014144000
18 17569457946995834880000
19 805912049524456562688000