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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 12 |
| 3 | 28 |
| 4 | 62 |
| 5 | 131 |
| 6 | 270 |
| 7 | 544 |
| 8 | 1079 |
| 9 | 2117 |
| 10 | 4111 |
| 11 | 7923 |
| 12 | 15167 |
| 13 | 28873 |
| 14 | 54700 |
| 15 | 103200 |
| 16 | 193993 |
| 17 | 363492 |
| 18 | 679141 |
| 19 | 1265643 |
| 20 | 2353204 |
| 21 | 4366164 |
| 22 | 8085640 |
| 23 | 14947693 |
| 24 | 27589371 |
| 25 | 50847817 |
| 26 | 93586753 |
| 27 | 172032816 |
| 28 | 315865168 |
| 29 | 579322476 |
| 30 | 1061447338 |
| 31 | 1942961421 |
| 32 | 3553392144 |
| 33 | 6493197325 |
[4,12,28,62,131,270,544,1079,2117,4111,7923,15167, 28873,54700,103200,193993,363492,679141,1265643, 2353204,4366164,8085640,14947693,27589371, 50847817,93586753,172032816,315865168,579322476, 1061447338,1942961421,3553392144,6493197325] |