# A251688 (b-file synthesized from sequence entry)
0 1
1 1
2 25
3 61
4 336
5 1200
6 3600
7 13500
8 32400
9 118800
10 259200
11 939600
12 1944000
13 6998400
14 13996800
15 50155200
16 97977600
17 349920000
18 671846400
19 2393452800
20 4534963200
21 16124313600
22 30233088000
23 107327462400
24 199538380800
25 707454259200
26 1306069401600
27 4625662464000
28 8489451110400