# A084219 (b-file synthesized from sequence entry)
0 1
1 -1
2 4
3 -8
4 20
5 -44
6 100
7 -220
8 484
9 -1052
10 2276
11 -4892
12 10468
13 -22300
14 47332
15 -100124
16 211172
17 -444188
18 932068
19 -1951516
20 4077796
21 -8505116
22 17709284
23 -36816668
24 76429540
25 -158451484
26 328087780
27 -678545180
28 1401829604