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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 4 |
| 2 | 14 |
| 3 | 40 |
| 4 | 101 |
| 5 | 236 |
| 6 | 518 |
| 7 | 1080 |
| 8 | 2162 |
| 9 | 4180 |
| 10 | 7840 |
| 11 | 14328 |
| 12 | 25591 |
| 13 | 44776 |
| 14 | 76918 |
| 15 | 129952 |
| 16 | 216240 |
| 17 | 354864 |
| 18 | 574958 |
| 19 | 920600 |
| 20 | 1457946 |
| 21 | 2285452 |
| 22 | 3548550 |
| 23 | 5460592 |
| 24 | 8332425 |
| 25 | 12614088 |
| 26 | 18953310 |
| 27 | 28276968 |
| 28 | 41904208 |
| 29 | 61702876 |
| 30 | 90304598 |
[1,4,14,40,101,236,518,1080,2162,4180,7840,14328, 25591,44776,76918,129952,216240,354864,574958, 920600,1457946,2285452,3548550,5460592,8332425, 12614088,18953310,28276968,41904208,61702876, 90304598] |