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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 7 |
| 4 | 28 |
| 5 | 77 |
| 6 | 326 |
| 7 | 1028 |
| 8 | 4508 |
| 9 | 15255 |
| 10 | 68726 |
| 11 | 244025 |
| 12 | 1118063 |
| 13 | 4116292 |
| 14 | 19085963 |
| 15 | 72237186 |
| 16 | 337973128 |
| 17 | 1307388767 |
| 18 | 6159989671 |
| 19 | 24254325742 |
| 20 | 114924609231 |
| 21 | 459192728592 |
| 22 | 2185841113614 |
| 23 | 8842628338991 |
| 24 | 42253748293080 |
| 25 | 172757264589725 |
| 26 | 828173559499092 |
| 27 | 3417317106698596 |
| 28 | 16427414281651963 |
[1,1,3,7,28,77,326,1028,4508,15255,68726,244025, 1118063,4116292,19085963,72237186,337973128, 1307388767,6159989671,24254325742,114924609231, 459192728592,2185841113614,8842628338991, 42253748293080,172757264589725,828173559499092, 3417317106698596,16427414281651963] |