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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 26 |
| 6 | 229 |
| 7 | 1246 |
| 8 | 5086 |
| 9 | 17084 |
| 10 | 49768 |
| 11 | 129958 |
| 12 | 311051 |
| 13 | 693290 |
| 14 | 1455909 |
| 15 | 2906436 |
| 16 | 5554172 |
| 17 | 10217000 |
| 18 | 18173272 |
| 19 | 31373636 |
| 20 | 52731365 |
| 21 | 86514106 |
| 22 | 138865053 |
| 23 | 218487442 |
| 24 | 337533050 |
| 25 | 512743140 |
| 26 | 766899120 |
| 27 | 1130650170 |
| 28 | 1644796335 |
| 29 | 2363118186 |
| 30 | 3355858221 |
| 31 | 4713974824 |
[0,0,0,1,26,229,1246,5086,17084,49768,129958, 311051,693290,1455909,2906436,5554172,10217000, 18173272,31373636,52731365,86514106,138865053, 218487442,337533050,512743140,766899120, 1130650170,1644796335,2363118186,3355858221, 4713974824] |