# A004393 (b-file synthesized from sequence entry)
12 1
13 104
14 6216
15 280840
16 10668000
17 359933112
18 11143364232
19 323295330680
20 8917061687820
21 236236542585120
22 6057158960772920
23 151175678720167920
24 3689062737122341488
25 88326646952501966400
26 2080775440409128608600