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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 21 |
| 5 | 69 |
| 6 | 190 |
| 7 | 446 |
| 8 | 927 |
| 9 | 1745 |
| 10 | 3036 |
| 11 | 4960 |
| 12 | 7701 |
| 13 | 11467 |
| 14 | 16490 |
| 15 | 23026 |
| 16 | 31355 |
| 17 | 41781 |
| 18 | 54632 |
| 19 | 70260 |
| 20 | 89041 |
| 21 | 111375 |
| 22 | 137686 |
| 23 | 168422 |
| 24 | 204055 |
| 25 | 245081 |
| 26 | 292020 |
| 27 | 345416 |
| 28 | 405837 |
| 29 | 473875 |
| 30 | 550146 |
| 31 | 635290 |
| 32 | 729971 |
| 33 | 834877 |
| 34 | 950720 |
| 35 | 1078236 |
| 36 | 1218185 |
| 37 | 1371351 |
| 38 | 1538542 |
| 39 | 1720590 |
[1,1,2,6,21,69,190,446,927,1745,3036,4960,7701, 11467,16490,23026,31355,41781,54632,70260,89041, 111375,137686,168422,204055,245081,292020,345416, 405837,473875,550146,635290,729971,834877,950720, 1078236,1218185,1371351,1538542,1720590] |