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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 21 |
| 5 | 73 |
| 6 | 222 |
| 7 | 563 |
| 8 | 1226 |
| 9 | 2376 |
| 10 | 4213 |
| 11 | 6972 |
| 12 | 10923 |
| 13 | 16371 |
| 14 | 23656 |
| 15 | 33153 |
| 16 | 45272 |
| 17 | 60458 |
| 18 | 79191 |
| 19 | 101986 |
| 20 | 129393 |
| 21 | 161997 |
| 22 | 200418 |
| 23 | 245311 |
| 24 | 297366 |
| 25 | 357308 |
| 26 | 425897 |
| 27 | 503928 |
| 28 | 592231 |
| 29 | 691671 |
| 30 | 803148 |
[1,2,6,21,73,222,563,1226,2376,4213,6972,10923, 16371,23656,33153,45272,60458,79191,101986,129393, 161997,200418,245311,297366,357308,425897,503928, 592231,691671,803148] |