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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 4 |
| 4 | 6 |
| 5 | 9 |
| 6 | 15 |
| 7 | 22 |
| 8 | 30 |
| 9 | 36 |
| 10 | 43 |
| 11 | 54 |
| 12 | 66 |
| 13 | 79 |
| 14 | 93 |
| 15 | 108 |
| 16 | 120 |
| 17 | 133 |
| 18 | 151 |
| 19 | 170 |
| 20 | 190 |
| 21 | 211 |
| 22 | 233 |
| 23 | 256 |
| 24 | 280 |
| 25 | 300 |
| 26 | 321 |
| 27 | 348 |
| 28 | 376 |
| 29 | 405 |
| 30 | 435 |
| 31 | 466 |
| 32 | 498 |
| 33 | 531 |
| 34 | 565 |
| 35 | 600 |
| 36 | 630 |
| 37 | 661 |
| 38 | 699 |
| 39 | 738 |
| 40 | 778 |
| 41 | 819 |
| 42 | 861 |
| 43 | 904 |
| 44 | 948 |
| 45 | 993 |
| 46 | 1039 |
| 47 | 1086 |
| 48 | 1134 |
| 49 | 1176 |
| 50 | 1219 |
| 51 | 1270 |
| 52 | 1322 |
| 53 | 1375 |
| 54 | 1429 |
| 55 | 1484 |
| 56 | 1540 |
[0,1,4,6,9,15,22,30,36,43,54,66,79,93,108,120,133, 151,170,190,211,233,256,280,300,321,348,376,405, 435,466,498,531,565,600,630,661,699,738,778,819, 861,904,948,993,1039,1086,1134,1176,1219,1270, 1322,1375,1429,1484,1540] |