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| n | a(n) |
|---|---|
| 1 | 4704 |
| 2 | 15572 |
| 3 | 51220 |
| 4 | 170568 |
| 5 | 569352 |
| 6 | 1912444 |
| 7 | 6442252 |
| 8 | 21811720 |
| 9 | 74044552 |
| 10 | 252514496 |
| 11 | 863227916 |
| 12 | 2963538436 |
| 13 | 10196465900 |
| 14 | 35222100660 |
| 15 | 121914919708 |
| 16 | 423563796488 |
| 17 | 1474316189604 |
| 18 | 5149747271896 |
| 19 | 18019152344164 |
| 20 | 63258132957568 |
[4704,15572,51220,170568,569352,1912444,6442252, 21811720,74044552,252514496,863227916,2963538436, 10196465900,35222100660,121914919708,423563796488, 1474316189604,5149747271896,18019152344164, 63258132957568] |