# A002463 (b-file synthesized from sequence entry)
1 1
2 3
3 30
4 175
5 4410
6 29106
7 396396
8 2760615
9 156434850
10 1122854590
11 16291599324
12 119224885962
13 3515605611700
14 26077294372500
15 388924218927000
16 2913690606794775
17 350671234206006450
18 2647224022927695750
19 40095381399899017500
20 304513870316075169750