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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 9 |
| 5 | 21 |
| 6 | 52 |
| 7 | 133 |
| 8 | 351 |
| 9 | 948 |
| 10 | 2610 |
| 11 | 7298 |
| 12 | 20672 |
| 13 | 59192 |
| 14 | 171059 |
| 15 | 498275 |
| 16 | 1461437 |
| 17 | 4312300 |
| 18 | 12792342 |
| 19 | 38128354 |
| 20 | 114126797 |
| 21 | 342914278 |
| 22 | 1033914760 |
| 23 | 3127154610 |
| 24 | 9485523742 |
| 25 | 28848101993 |
| 26 | 87948036401 |
| 27 | 268724650863 |
| 28 | 822791384597 |
| 29 | 2524113596369 |
| 30 | 7757247543181 |
| 31 | 23880003051017 |
| 32 | 73627904162143 |
| 33 | 227347168628991 |
| 34 | 702970760225573 |
| 35 | 2176459051318522 |
[1,1,2,4,9,21,52,133,351,948,2610,7298,20672, 59192,171059,498275,1461437,4312300,12792342, 38128354,114126797,342914278,1033914760, 3127154610,9485523742,28848101993,87948036401, 268724650863,822791384597,2524113596369, 7757247543181,23880003051017,73627904162143, 227347168628991,702970760225573,2176459051318522] |