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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 12 |
| 4 | 62 |
| 5 | 253 |
| 6 | 804 |
| 7 | 2136 |
| 8 | 4958 |
| 9 | 10376 |
| 10 | 20013 |
| 11 | 36144 |
| 12 | 61846 |
| 13 | 101163 |
| 14 | 159286 |
| 15 | 242748 |
| 16 | 359634 |
| 17 | 519806 |
| 18 | 735143 |
| 19 | 1019796 |
| 20 | 1390458 |
| 21 | 1866649 |
| 22 | 2471016 |
| 23 | 3229648 |
| 24 | 4172406 |
| 25 | 5333268 |
| 26 | 6750689 |
| 27 | 8467976 |
| 28 | 10533678 |
| 29 | 13001991 |
| 30 | 15933178 |
| 31 | 19394004 |
[0,1,12,62,253,804,2136,4958,10376,20013,36144, 61846,101163,159286,242748,359634,519806,735143, 1019796,1390458,1866649,2471016,3229648,4172406, 5333268,6750689,8467976,10533678,13001991, 15933178,19394004] |