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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 10 |
| 3 | 25 |
| 4 | 64 |
| 5 | 154 |
| 6 | 363 |
| 7 | 820 |
| 8 | 1811 |
| 9 | 3873 |
| 10 | 8161 |
| 11 | 16682 |
| 12 | 33757 |
| 13 | 66865 |
| 14 | 130938 |
| 15 | 251983 |
| 16 | 480794 |
| 17 | 903982 |
| 18 | 1685564 |
| 19 | 3106009 |
| 20 | 5677864 |
| 21 | 10276936 |
| 22 | 18464659 |
| 23 | 32891188 |
| 24 | 58169965 |
| 25 | 102136773 |
| 26 | 178096365 |
| 27 | 308593320 |
| 28 | 531191385 |
| 29 | 909227947 |
| 30 | 1546356486 |
| 31 | 2617639293 |
[4,10,25,64,154,363,820,1811,3873,8161,16682, 33757,66865,130938,251983,480794,903982,1685564, 3106009,5677864,10276936,18464659,32891188, 58169965,102136773,178096365,308593320,531191385, 909227947,1546356486,2617639293] |