# A218034 (b-file synthesized from sequence entry)
0 1
1 4
2 12
3 24
4 84
5 240
6 732
7 2184
8 6564
9 19680
10 59052
11 177144
12 531444
13 1594320
14 4782972
15 14348904
16 43046724
17 129140160
18 387420492
19 1162261464
20 3486784404
21 10460353200
22 31381059612
23 94143178824
24 282429536484
25 847288609440
26 2541865828332
27 7625597484984
28 22876792454964