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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 16 |
| 5 | 42 |
| 6 | 147 |
| 7 | 454 |
| 8 | 1628 |
| 9 | 5425 |
| 10 | 20178 |
| 11 | 70153 |
| 12 | 268235 |
| 13 | 962420 |
| 14 | 3748820 |
| 15 | 13809050 |
| 16 | 54492862 |
| 17 | 204977746 |
| 18 | 817599476 |
| 19 | 3126108027 |
| 20 | 12586411942 |
| 21 | 48758462507 |
| 22 | 197878414706 |
| 23 | 775091653268 |
| 24 | 3166333356578 |
| 25 | 12521930286700 |
| 26 | 51439036172347 |
| 27 | 205114689753037 |
| 28 | 846727775491103 |
| 29 | 3400496099226738 |
[1,1,2,5,16,42,147,454,1628,5425,20178,70153, 268235,962420,3748820,13809050,54492862,204977746, 817599476,3126108027,12586411942,48758462507, 197878414706,775091653268,3166333356578, 12521930286700,51439036172347,205114689753037, 846727775491103,3400496099226738] |