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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 8 |
| 3 | 32 |
| 4 | 167 |
| 5 | 740 |
| 6 | 3278 |
| 7 | 13994 |
| 8 | 58595 |
| 9 | 241250 |
| 10 | 982016 |
| 11 | 3959736 |
| 12 | 15848648 |
| 13 | 63063260 |
| 14 | 249773862 |
| 15 | 985585668 |
| 16 | 3877333900 |
| 17 | 15216566840 |
| 18 | 59600223620 |
| 19 | 233072224782 |
| 20 | 910286934007 |
| 21 | 3551576307448 |
| 22 | 13845532229952 |
| 23 | 53940983618522 |
[0,8,32,167,740,3278,13994,58595,241250,982016, 3959736,15848648,63063260,249773862,985585668, 3877333900,15216566840,59600223620,233072224782, 910286934007,3551576307448,13845532229952, 53940983618522] |