n | a(n) |
---|---|
1 | 1 |
2 | 0 |
3 | 1 |
4 | 4 |
5 | 15 |
6 | 40 |
7 | 144 |
8 | 512 |
9 | 1841 |
10 | 6528 |
11 | 23808 |
12 | 87380 |
13 | 322875 |
14 | 1198080 |
15 | 4473647 |
16 | 16777216 |
17 | 63164175 |
18 | 238605640 |
19 | 904200192 |
20 | 3435973836 |
21 | 13089461538 |
22 | 49977753600 |
23 | 191219367936 |
24 | 733007751680 |
25 | 2814750270420 |
26 | 10825959997440 |
27 | 41699995927744 |
28 | 160842843834660 |
[1,0,1,4,15,40,144,512,1841,6528,23808,87380, 322875,1198080,4473647,16777216,63164175, 238605640,904200192,3435973836,13089461538, 49977753600,191219367936,733007751680, 2814750270420,10825959997440,41699995927744, 160842843834660] |