# A169418 (b-file synthesized from sequence entry)
0 1
1 21
2 420
3 8400
4 168000
5 3360000
6 67200000
7 1344000000
8 26880000000
9 537600000000
10 10752000000000
11 215040000000000
12 4300800000000000
13 86016000000000000
14 1720320000000000000
15 34406400000000000000