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| n | a(n) |
|---|---|
| 0 | 3 |
| 1 | 8 |
| 2 | 20 |
| 3 | 53 |
| 4 | 154 |
| 5 | 505 |
| 6 | 1944 |
| 7 | 8651 |
| 8 | 44046 |
| 9 | 252271 |
| 10 | 1605874 |
| 11 | 11245261 |
| 12 | 85907084 |
| 13 | 710970323 |
| 14 | 6336648426 |
| 15 | 60510526207 |
| 16 | 616355168958 |
| 17 | 6670526004559 |
| 18 | 76438597647616 |
| 19 | 924584128977111 |
| 20 | 11772170758462928 |
| 21 | 157382330019694067 |
| 22 | 2204239468545788024 |
| 23 | 32275035859881159165 |
[3,8,20,53,154,505,1944,8651,44046,252271,1605874, 11245261,85907084,710970323,6336648426, 60510526207,616355168958,6670526004559, 76438597647616,924584128977111,11772170758462928, 157382330019694067,2204239468545788024, 32275035859881159165] |