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| n | a(n) |
|---|---|
| 1 | 31 |
| 2 | 216 |
| 3 | 1500 |
| 4 | 10428 |
| 5 | 72468 |
| 6 | 503676 |
| 7 | 3500532 |
| 8 | 24329052 |
| 9 | 169088148 |
| 10 | 1175174460 |
| 11 | 8167536180 |
| 12 | 56764911132 |
| 13 | 394519788756 |
| 14 | 2741938101756 |
| 15 | 19056647102580 |
| 16 | 132444930680028 |
| 17 | 920500836944148 |
| 18 | 6397540377615036 |
| 19 | 44463319555825332 |
[31,216,1500,10428,72468,503676,3500532,24329052, 169088148,1175174460,8167536180,56764911132, 394519788756,2741938101756,19056647102580, 132444930680028,920500836944148,6397540377615036, 44463319555825332] |