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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 2 |
| 5 | 6 |
| 6 | 22 |
| 7 | 92 |
| 8 | 419 |
| 9 | 2066 |
| 10 | 10863 |
| 11 | 60459 |
| 12 | 354381 |
| 13 | 2177439 |
| 14 | 13979759 |
| 15 | 93527819 |
| 16 | 650509643 |
| 17 | 4694372980 |
| 18 | 35086564926 |
| 19 | 271174745565 |
| 20 | 2164066408692 |
| 21 | 17808271012127 |
| 22 | 150925549288155 |
| 23 | 1315804758238582 |
| 24 | 11787981398487995 |
| 25 | 108409978503340041 |
| 26 | 1022519935940220983 |
| 27 | 9882436548778410911 |
| 28 | 97788364370359938816 |
[1,1,1,1,2,6,22,92,419,2066,10863,60459,354381, 2177439,13979759,93527819,650509643,4694372980, 35086564926,271174745565,2164066408692, 17808271012127,150925549288155,1315804758238582, 11787981398487995,108409978503340041, 1022519935940220983,9882436548778410911, 97788364370359938816] |