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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 48 |
| 4 | 423 |
| 5 | 3082 |
| 6 | 18998 |
| 7 | 133083 |
| 8 | 965175 |
| 9 | 6907447 |
| 10 | 48357538 |
| 11 | 337492571 |
| 12 | 2379164196 |
| 13 | 16812509746 |
| 14 | 118525108279 |
| 15 | 834050273099 |
| 16 | 5871294215587 |
| 17 | 41366373307538 |
| 18 | 291469733924989 |
| 19 | 2053121255070040 |
| 20 | 14460522145205162 |
| 21 | 101855876591455305 |
| 22 | 717493569094700741 |
[1,1,5,48,423,3082,18998,133083,965175,6907447, 48357538,337492571,2379164196,16812509746, 118525108279,834050273099,5871294215587, 41366373307538,291469733924989,2053121255070040, 14460522145205162,101855876591455305, 717493569094700741] |