# A005397 (b-file synthesized from sequence entry)
3 4
4 0
5 0
6 4
7 28
8 80
9 120
10 120
11 264
12 1080
13 3120
14 6440
15 11960
16 26688
17 70448
18 179340
19 415796
20 935560
21 2195536
22 5374468
23 13145420
24 31504224
25 74955600
26 180228984
27 438624648
28 1069909344
29 2600077824
30 6310088640
31 15363918432