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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 6 |
| 3 | 19 |
| 4 | 69 |
| 5 | 267 |
| 6 | 1093 |
| 7 | 4629 |
| 8 | 20142 |
| 9 | 89473 |
| 10 | 404076 |
| 11 | 1849746 |
| 12 | 8563558 |
| 13 | 40025574 |
| 14 | 188612388 |
| 15 | 895115942 |
| 16 | 4274453904 |
| 17 | 20523807009 |
| 18 | 99025615998 |
| 19 | 479874362583 |
| 20 | 2334582421497 |
| 21 | 11398055887003 |
| 22 | 55828060595832 |
| 23 | 274254002718255 |
| 24 | 1350907899813921 |
| 25 | 6670789629569022 |
[1,3,6,19,69,267,1093,4629,20142,89473,404076, 1849746,8563558,40025574,188612388,895115942, 4274453904,20523807009,99025615998,479874362583, 2334582421497,11398055887003,55828060595832, 274254002718255,1350907899813921,6670789629569022] |