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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 7 |
| 4 | 26 |
| 5 | 101 |
| 6 | 462 |
| 7 | 2528 |
| 8 | 15108 |
| 9 | 92443 |
| 10 | 581138 |
| 11 | 3910688 |
| 12 | 29024316 |
| 13 | 234464634 |
| 14 | 1982157166 |
| 15 | 17009089378 |
| 16 | 147132511520 |
| 17 | 1301376431363 |
| 18 | 12058326893970 |
| 19 | 119068705590380 |
| 20 | 1249031077693044 |
| 21 | 13641953001474076 |
| 22 | 151668261047351986 |
[1,1,2,7,26,101,462,2528,15108,92443,581138, 3910688,29024316,234464634,1982157166,17009089378, 147132511520,1301376431363,12058326893970, 119068705590380,1249031077693044, 13641953001474076,151668261047351986] |