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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | 2 |
| 6 | 5 |
| 7 | 9 |
| 8 | 22 |
| 9 | 60 |
| 10 | 164 |
| 11 | 494 |
| 12 | 1624 |
| 13 | 5602 |
| 14 | 20600 |
| 15 | 79813 |
| 16 | 323806 |
| 17 | 1371025 |
| 18 | 6034105 |
| 19 | 27513424 |
| 20 | 129641411 |
| 21 | 629862824 |
| 22 | 3149541908 |
| 23 | 16183100922 |
| 24 | 85328280263 |
| 25 | 461123500894 |
| 26 | 2551342936264 |
| 27 | 14438734591483 |
| 28 | 83506198920054 |
| 29 | 493163726073210 |
| 30 | 2971858162771887 |
[1,0,0,1,1,2,5,9,22,60,164,494,1624,5602,20600, 79813,323806,1371025,6034105,27513424,129641411, 629862824,3149541908,16183100922,85328280263, 461123500894,2551342936264,14438734591483, 83506198920054,493163726073210,2971858162771887] |