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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 9 |
| 3 | 40 |
| 4 | 282 |
| 5 | 1455 |
| 6 | 7278 |
| 7 | 29849 |
| 8 | 107399 |
| 9 | 330369 |
| 10 | 890152 |
| 11 | 2096153 |
| 12 | 4364470 |
| 13 | 8045195 |
| 14 | 13215574 |
| 15 | 19368689 |
| 16 | 25423509 |
| 17 | 29898089 |
| 18 | 31566122 |
| 19 | 29898089 |
| 20 | 25423509 |
| 21 | 19368689 |
| 22 | 13215574 |
| 23 | 8045195 |
| 24 | 4364470 |
| 25 | 2096153 |
| 26 | 890152 |
| 27 | 330369 |
| 28 | 107399 |
| 29 | 29849 |
[1,1,9,40,282,1455,7278,29849,107399,330369, 890152,2096153,4364470,8045195,13215574,19368689, 25423509,29898089,31566122,29898089,25423509, 19368689,13215574,8045195,4364470,2096153,890152, 330369,107399,29849] |