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| n | a(n) |
|---|---|
| 0 | 2 |
| 1 | 4 |
| 2 | 7 |
| 3 | 11 |
| 4 | 20 |
| 5 | 38 |
| 6 | 70 |
| 7 | 130 |
| 8 | 245 |
| 9 | 461 |
| 10 | 866 |
| 11 | 1630 |
| 12 | 3070 |
| 13 | 5780 |
| 14 | 10883 |
| 15 | 20495 |
| 16 | 38596 |
| 17 | 72682 |
| 18 | 136874 |
| 19 | 257762 |
| 20 | 485417 |
| 21 | 914137 |
| 22 | 1721506 |
| 23 | 3241946 |
| 24 | 6105242 |
| 25 | 11497412 |
| 26 | 21651967 |
| 27 | 40775059 |
| 28 | 76787732 |
| 29 | 144606926 |
| 30 | 272324270 |
| 31 | 512842018 |
| 32 | 965785885 |
| 33 | 1818771365 |
| 34 | 3425116610 |
[2,4,7,11,20,38,70,130,245,461,866,1630,3070,5780, 10883,20495,38596,72682,136874,257762,485417, 914137,1721506,3241946,6105242,11497412,21651967, 40775059,76787732,144606926,272324270,512842018, 965785885,1818771365,3425116610] |