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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 10 |
| 6 | 53 |
| 7 | 98 |
| 8 | 397 |
| 9 | 1058 |
| 10 | 3341 |
| 11 | 9658 |
| 12 | 30053 |
| 13 | 87386 |
| 14 | 267877 |
| 15 | 793682 |
| 16 | 2397437 |
| 17 | 7162066 |
| 18 | 21552125 |
| 19 | 64506026 |
| 20 | 193839445 |
| 21 | 580889738 |
| 22 | 1743836117 |
| 23 | 5229312706 |
| 24 | 15692323949 |
| 25 | 47067796610 |
| 26 | 141222563821 |
| 27 | 423628907162 |
| 28 | 1270962692165 |
| 29 | 3812740639930 |
[1,0,1,2,5,10,53,98,397,1058,3341,9658,30053, 87386,267877,793682,2397437,7162066,21552125, 64506026,193839445,580889738,1743836117, 5229312706,15692323949,47067796610,141222563821, 423628907162,1270962692165,3812740639930] |