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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 28 |
| 2 | 184 |
| 3 | 952 |
| 4 | 5776 |
| 5 | 35448 |
| 6 | 222952 |
| 7 | 1420496 |
| 8 | 9147088 |
| 9 | 59375320 |
| 10 | 387912604 |
| 11 | 2547709060 |
| 12 | 16806321736 |
| 13 | 111277617648 |
| 14 | 739135427676 |
| 15 | 4923070227492 |
| 16 | 32869506283728 |
| 17 | 219923274753560 |
| 18 | 1474233675264148 |
| 19 | 9898993676048540 |
[1,28,184,952,5776,35448,222952,1420496,9147088, 59375320,387912604,2547709060,16806321736, 111277617648,739135427676,4923070227492, 32869506283728,219923274753560,1474233675264148, 9898993676048540] |