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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 13 |
| 6 | 32 |
| 7 | 83 |
| 8 | 225 |
| 9 | 638 |
| 10 | 1871 |
| 11 | 5651 |
| 12 | 17537 |
| 13 | 55772 |
| 14 | 181348 |
| 15 | 601754 |
| 16 | 2034368 |
| 17 | 6997316 |
| 18 | 24456376 |
| 19 | 86764857 |
| 20 | 312157366 |
| 21 | 1137925574 |
| 22 | 4199870789 |
| 23 | 15683541837 |
| 24 | 59220398058 |
| 25 | 225982562259 |
| 26 | 871031643495 |
| 27 | 3389581971377 |
| 28 | 13311468152196 |
[1,1,2,5,13,32,83,225,638,1871,5651,17537,55772, 181348,601754,2034368,6997316,24456376,86764857, 312157366,1137925574,4199870789,15683541837, 59220398058,225982562259,871031643495, 3389581971377,13311468152196] |